U.S. patent application number 15/393360 was filed with the patent office on 2017-04-20 for heteroatom containing cyclic dimers.
The applicant listed for this patent is Novus International, Inc.. Invention is credited to Graciela B. Arhancet, Matthew Mahoney, Xiaojun Wang.
Application Number | 20170107192 15/393360 |
Document ID | / |
Family ID | 48945720 |
Filed Date | 2017-04-20 |
United States Patent
Application |
20170107192 |
Kind Code |
A1 |
Arhancet; Graciela B. ; et
al. |
April 20, 2017 |
HETEROATOM CONTAINING CYCLIC DIMERS
Abstract
The present invention provides cyclic dimers of alpha acids and
polymers derived therefrom. Also provided are processes for
preparing and methods of using the cyclic dimers and the polymers
derived from the cyclic dimers.
Inventors: |
Arhancet; Graciela B.; (St.
Charles, MO) ; Mahoney; Matthew; (St. Charles,
MO) ; Wang; Xiaojun; (St. Charles, MO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Novus International, Inc. |
St. Charles |
MO |
US |
|
|
Family ID: |
48945720 |
Appl. No.: |
15/393360 |
Filed: |
December 29, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14639668 |
Mar 5, 2015 |
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15393360 |
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13763101 |
Feb 8, 2013 |
9011832 |
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14639668 |
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61596843 |
Feb 9, 2012 |
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61597444 |
Feb 10, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A23K 50/75 20160501;
C08G 63/6882 20130101; C08G 63/85 20130101; A23K 20/10 20160501;
C07D 319/12 20130101; A23K 50/10 20160501; C08L 67/04 20130101;
C08L 67/00 20130101; C08G 75/02 20130101; C07D 265/33 20130101;
C08G 67/00 20130101 |
International
Class: |
C07D 319/12 20060101
C07D319/12; C08G 63/85 20060101 C08G063/85; C08L 67/00 20060101
C08L067/00; C08G 63/688 20060101 C08G063/688 |
Claims
1. A process for forming a polymer comprising repeat units of
Formula (XX), the process comprising heating a plurality of
monomers of Formula (II) to a temperature from about 100.degree. C.
to about 200.degree. C. such that the monomers form the polymer
comprising repeat units of Formula (XX): ##STR00110## wherein:
R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are independently
hydrogen, hydrocarbyl, or substituted hydrocarbyl; R.sup.6 is
hydrogen, hydrocarbyl, or substituted hydrocarbyl; R.sup.7 is not
present; Z is sulfur, sulfone, sulfoxide, or selenium; and n is an
integer .gtoreq.1.
2. The process of claim 1, wherein R.sup.1 is hydrogen, alkyl, or
substituted alkyl, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are
hydrogen; R.sup.6 is C.sub.1-C.sub.6 alkyl; and n is from 1 to
10.
3. The process of claim 1, wherein the plurality of monomers have
Formula (IIa) and the polymer comprises repeat units of Formula
(XXa): ##STR00111## wherein: R.sup.2, R.sup.3, R.sup.4, R.sup.5,
R.sup.6, R.sup.8, R.sup.9, and R.sup.10 are independently hydrogen,
alkyl, or substituted alkyl; R.sup.7 and R.sup.11 are not present;
Y and Z are independently sulfur, sulfone, sulfoxide, or selenium;
and n and m are integers .gtoreq.1.
4. The process of claim 3, wherein R.sup.2, R.sup.3, R.sup.4,
R.sup.5, R.sup.8 and R.sup.9 are hydrogen; R.sup.6 and R.sup.10 are
C.sub.1-C.sub.6 alkyl; and each of n and m is from 1 to 10.
5. The process of claim 4, wherein R.sup.6 and R.sup.10 are methyl;
Y and Z are sulfur, and each of n and m is 2.
6. The process of claim 1, wherein the polymer comprising repeat
units of Formula (XX) has a number average molecular weight of at
least about 2,000 Da, at least about 10,000 Da, at least about
100,000 Da, or at least about 1,000,000 Da.
7. The process of claim 1, wherein the polymer comprising repeat
units of Formula (XX) contains less than about 5% by weight of free
monomer.
8. The process of claim 1, wherein the reaction is conducted in the
absence or presence of a catalyst.
9. The process of claim 1, wherein the temperature is from about
120.degree. C. to about 180.degree. C.
10. The process of claim 1, wherein the heating occurs in an
extruder, the extruder being a twin screw extruder, a single screw
extruder, or an extruder thermoforming machine.
11. An extrudate prepared by the process of claim 10.
12. The process of claim 1, wherein the process further comprises
heating in the presence of a plurality of additional monomers to
form a copolymer.
13. The process of claim 12, wherein the plurality of additional
monomers is chosen from acrylates, aminoacrylates, alkylene
succinates, alkylene oxalates, amides, amino acids, anhydrides,
arylates, carbonates, celluloses, caprolactones, caprolactams,
cyanoacrylates, cyclic ethers, dihydropyrans, dioxanes, dioxanones,
ether ether ketones, ethylene glycols, fumarates, hydroxy
alkanoates, hydroxy esters, imides, ketals, lactides, lactones,
lactams, methacrylates, methyl olefins, orthoesters, phosphazines,
styrenes, terephthalates, tetrafurans, trimethylene carbonates,
urethanes, vinyl acetates, vinyl ketones, or vinyl halides.
14. The process of claim 13, wherein the additional monomers are
lactides, lactones, lactams, hydroxy alkanoates, or hydroxy
esters.
15. The process of claim 12, wherein the reaction is conducted in
the absence or presence of a catalyst.
16. The process of claim 12, wherein the temperature is from about
120.degree. C. to about 180.degree. C.
17. The process of claim 12, wherein the heating occurs in an
extruder, the extruder being a twin screw extruder, a single screw
extruder, or an extruder thermoforming machine.
18. An extrudate prepared by the process of claim 17.
19. The process of claim 1 further comprising heating in the
presence of a polymer comprising at least one hydroxyl or amine
group.
20. The process of claim 19, wherein the polymer is a polylactide,
polylactone, polylactam, polyolefin, polymethacrylate,
polyhydroxyalkanoate, poly hydroxy ester, cellulose, or starch.
21. The process of claim 19, wherein the reaction is conducted in
the absence or presence of a catalyst.
22. The process of claim 19, wherein the temperature is from about
120.degree. C. to about 180.degree. C.
23. The process of claim 19, wherein the heating occurs in an
extrude, the extruder being a twin screw extruder, a single screw
extruder, or an extruder thermoforming machine.
24. An extrudate prepared by the process of claim 23.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 14/639,668, filed Mar. 5, 2015, which is a divisional of U.S.
application Ser. No. 13/763,101, now U.S. Pat. No. 9,011,832, filed
Feb. 8, 2013, which claims priority to U.S. Provisional Application
No. 61/596,843, filed Feb. 9, 2012, and U.S. Provisional
Application No. 61/597,444, filed Feb. 10, 2012, the disclosure of
each is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to cyclic dimers of alpha acids and
polymers derived therefrom, processes for preparing and methods of
using cyclic dimers and polymers derived therefrom.
BACKGROUND OF THE INVENTION
[0003] Alpha acids are important molecules for a variety of
purposes including as industrial chemicals, feed additives,
therapeutics, and various other uses. Alpha acids include, for
example, amino acids and alpha hydroxy acids. When two alpha acids
react, they can form linear or cyclic dimers. When alpha acids
react to form cyclic dimers the acid moiety is no longer free, and
thus the cyclic dimers can have different physical properties such
as reactivity, stability, and solubility, that can be advantageous
for certain applications.
[0004] For example, cyclic dimers can be used as compounds capable
of releasing alpha acids. Cyclic dimers of alpha acids also may
provide important routes for synthesizing polymers and copolymers
of alpha acids. For example, lactic acid cyclic dimers, also called
lactides, provide an important route to polylactic acid, an
important polymer which has attracted significant interest due to
its properties of being biocompatible and biodegradable, and for
its suitability for uses in the biomedical and industrial fields.
Formation of lactide from lactic acid is complicated by competing
oligomerization reactions. Most processes developed for producing
lactide compounds involved treatment at high temperatures under a
vacuum. For example, U.S. Pat. No. 5,274,073 describes production
of lactide by evaporating water from lactic acid to give an
oligomer, and then mixing the oligomer with a depolymerization
catalyst followed by thermal cracking to produce the lactide as a
vapor.
[0005] Unlike lactide, cyclic dimers of alpha acids with heteroatom
side chain moieties have not been synthesized using the thermal
cracking process. Heteroatom substituted cyclic dimers are
desirable compounds because they can provide important
functionalities for the numerous applications of the cyclic
compounds. For example, substituted cyclic dimers may provide
routes to functionalized and structurally diverse (i.e. branched,
star, block) polymers and copolymers, which may have different or
enhanced properties over polylactic acid. Other methods for
synthesizing cyclic dimers have also failed for heteroatom
containing alpha acids. A theoretical route to forming the cyclic
compounds from reaction of the halogen substituted monomers give
poor yields because the halogenated monomer is unstable. Thus,
routes to functionalized cyclic dimers of alpha acids remain a
synthetic challenge.
[0006] Thus, there is a need for heteroatom containing cyclic
dimers as well as processes for making them.
SUMMARY OF THE INVENTION
[0007] The present invention relates to cyclic dimers of alpha
acids, polymers prepared from cyclic dimers of alpha acids, methods
for preparing cyclic dimers and polymers prepared therefrom, and
uses of the cyclic dimers and polymers.
[0008] A first aspect of the invention encompasses a compound
comprising Formula (I):
##STR00001##
[0009] wherein, [0010] X.sup.1 and X.sup.2 are chosen from nitrogen
and oxygen, provided that both X.sup.1 and X.sup.2 are not
nitrogen; [0011] R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5
are independently chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0012] R.sup.6 is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0013] R.sup.7 is
optionally present, when present it is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0014] Z is chosen from
nitrogen, sulfur, sulfone, sulfoxide, and selenium; and [0015] n is
an integer .gtoreq.1; [0016] provided that when Z is sulfur and n
is 1, then R.sup.1 and R.sup.3 are other than hydrogen; and when Z
is nitrogen, n is from 2 to 4, and R.sup.3 is hydrogen, then
R.sup.1 is other than hydrogen or methyl.
[0017] Another aspect of the present disclosure provides a process
for preparing a compound comprising Formula (IX). The process
comprises (a) contacting a compound comprising Formula (VI) with a
compound comprising Formula (VII) or a compound comprising Formula
(VIII) and an acid catalyst and (b) dehydrating the resulting
reaction mixture to form the compound comprising Formula (IX), the
compounds comprising Formula (IX), (VI), (VII), and (VIII):
##STR00002##
[0018] wherein, [0019] X.sup.1 is chosen from oxygen and nitrogen,
[0020] R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are
independently chosen from hydrogen, hydrocarbyl, and substituted
hydrocarbyl; [0021] R.sup.6 is chosen from hydrogen, hydrocarbyl,
and substituted hydrocarbyl; [0022] R.sup.7 is optionally present,
when present it is chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0023] Z is chosen from nitrogen, sulfur,
sulfone, sulfoxide, and selenium; and [0024] n is an integer
.gtoreq.1.
[0025] A further aspect of the disclosure encompasses another
method for preparing a compound comprising Formula (IX). The
process comprises (a) heating a compound comprising Formula (VI)
with a compound comprising Formula (VII) or a compound comprising
Formula (VIII) to form a polymer and (b) heating the polymer at a
temperature of about 200.degree. C. and a pressure of less than
about 1 Torr to form the compound comprising Formula (IX), the
compounds comprising Formula (IX), (VI), (VII), and (VIII):
##STR00003##
[0026] wherein, [0027] X.sup.1 is chosen from oxygen and nitrogen,
[0028] R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are
independently chosen from hydrogen, hydrocarbyl, and substituted
hydrocarbyl; [0029] R.sup.6 is chosen from hydrogen, hydrocarbyl,
and substituted hydrocarbyl; [0030] R.sup.7 is optionally present,
when present it is chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0031] Z is chosen from nitrogen, sulfur,
sulfone, sulfoxide, and selenium; and [0032] n is an integer
.gtoreq.1.
[0033] Yet another aspect provides a polymer comprising a repeat
unit comprising Formula (XX):
##STR00004##
[0034] wherein: [0035] R.sup.1, R.sup.2, R.sup.3, R.sup.4, and
R.sup.5 are independently chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0036] R.sup.6 is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0037] R.sup.7 is
optionally present, when present it is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0038] Z is chosen from
nitrogen, sulfur, sulfone, sulfoxide, and selenium; and [0039] n is
an integer .gtoreq.1.
[0040] Still another aspect of the present disclosure provides a
polymer comprising Formula (XXI):
##STR00005##
[0041] wherein: [0042] R is chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0043] X is chosen from oxygen and
nitrogen; and [0044] p is an integer greater than 1.
[0045] An additional aspect of the disclosure encompasses a process
for forming a polymer. The process comprises contacting a plurality
of compounds comprising Formula (II):
##STR00006## [0046] with a catalyst to form the polymer comprising
a repeat unit comprising Formula (XX):
##STR00007##
[0047] wherein: [0048] R.sup.1, R.sup.2, R.sup.3, R.sup.4, and
R.sup.5 are independently chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0049] R.sup.6 is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0050] R.sup.7 is
optionally present, when present it is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0051] Z is chosen from
nitrogen, sulfur, sulfone, sulfoxide, and selenium; and [0052] n is
an integer .gtoreq.1.
[0053] Other features and iterations of the invention are described
in more detail herein.
BRIEF DESCRIPTION OF DRAWINGS
[0054] The patent or application file contains at least one drawing
executed in color. Copies of this patent or patent application
publication with color drawing(s) will be provided by the Office
upon request and payment of the necessary fee.
[0055] FIG. 1A-B shows the products formed after reaction of
2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) with hydrochloric
acid. FIG. 1A shows an HPLC chromatogram in which the different
products are identified. FIG. 1B shows the same chromatogram as in
FIG. 1A that is overlayed with a chromatogram showing the elution
profile of 3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione.
[0056] FIG. 2A-B shows the products formed after azeotropic
distillation of 2-hydroxy-4-(methylthio)-butanoic acid (HMTBA).
FIG. 2A shows an HPLC chromatogram in which the different compounds
are identified. FIG. 2B shows the same chromatogram as in (FIG. 2A)
that is overlayed with a chromatogram showing the elution profile
of 3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione.
[0057] FIG. 3 presents an .sup.1H NMR spectrum demonstrating the
structure of the polymer prepared from
3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione.
[0058] FIG. 4 shows gel permeation chromatograph traces monitoring
ring opening polymerization of
3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione as a function of
time.
[0059] FIG. 5 presents an HPLC chromatogram of the reaction mixture
of ring opening polymerization of
3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione at 24 hours.
[0060] FIG. 6 shows HPLC analysis of the reaction mixture of the
product shown in FIG. 5 after 2 hours of distillation at
200.degree. C., 500 mTorr.
[0061] FIG. 7 presents HPLC analysis of distillates of the
depolymerization reaction after 2 hours of distillation at
200.degree. C., 500 mTorr.
[0062] FIG. 8 presents an HPLC chromatogram of distillates of the
depolymerization reaction of polymer formed from HMTBa.
DETAILED DESCRIPTION OF THE INVENTION
[0063] The present invention provides cyclic dimers of alpha acids
that may be used for many purposes. The invention also provides
methods for making the cyclic dimers, compositions comprising the
cyclic dimers, and methods of using the cyclic dimers. Also
provided are polymers prepared from the cyclic dimers, methods for
preparing the polymers, and compositions comprising the polymers.
Advantageously, polymers of very high molecular weight can be
prepared from the cyclic dimers. The cyclic dimers and the polymers
prepared from these cyclic dimers may be used, for example, as
plasticizers, additives, processing aids, nutritive agents,
antioxidant agents, antimicrobial agents, and feed additives.
[0064] The cyclic dimers of alpha acids, as disclosed herein, have
the general structure shown below. For purposes of discussion, the
ring atoms are numbered 1 to 6. Substitutions at the 3- and the
6-position may be described as pendant groups to the cyclic
structure. Where no stereochemistry is shown, it is intended to
represent any stereochemistry.
##STR00008##
(I) Cyclic Dimer Compounds
[0065] One aspect of the invention provides cyclic dimer compounds
comprising Formula (I):
##STR00009##
[0066] wherein, [0067] X.sup.1 and X.sup.2 are independently chosen
from nitrogen and oxygen, provided that both X.sup.1 and X.sup.2
are other than nitrogen; [0068] R.sup.1, R.sup.2, R.sup.3, R.sup.4,
and R.sup.5 are independently chosen from hydrogen, hydrocarbyl,
and substituted hydrocarbyl; [0069] R.sup.6 is chosen from
hydrogen, hydrocarbyl, and substituted hydrocarbyl; [0070] R.sup.7
is optionally present, when present it is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0071] Z is chosen from
nitrogen, sulfur, sulfone, sulfoxide, and selenium; and [0072] n is
an integer .gtoreq.1; [0073] provided that when Z is sulfur and n
is 1, then R.sup.1 and R.sup.3 are other than hydrogen; and when Z
is nitrogen, n is from 2 to 4, and R.sup.3 is hydrogen, then
R.sup.1 is other than hydrogen or methyl.
[0074] The heteroatoms, X.sup.1 and X.sup.2, at the 1- and
4-positions of the ring are independently chosen from nitrogen and
oxygen, provided that both are not nitrogen. In some embodiments,
the heteroatoms are in their neutral state. Thus, where X.sup.1 or
X.sup.2 is nitrogen, the nitrogen atom may be further substituted
with another substituent. Additional substitutions of the
heteroatom are preferably hydrogen, but may be chosen from various
other groups known in the art. In other embodiments, the
heteroatoms may hold a charge. In some embodiments, X.sup.1 and
X.sup.2 are both oxygen. In other embodiments, X.sup.1 is nitrogen
and X.sup.2 is oxygen. In still another embodiment, X.sup.1 is
oxygen and X.sup.2 is nitrogen.
[0075] Each of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5,
R.sup.6, and R.sup.7 may be chosen from hydrogen, hydrocarbyl, or
substituted hydrocarbyl. In various embodiments, the hydrocarbyl
may be, but is not limited to, alkyl, cycloalkyl, alkenyl,
alkenoxy, aryl, or alkylaryl. Substituted hydrocarbyl may be,
without limit, arylalkoxyl, alkoxy, alkoxycarbonyl, carbonyl, acyl,
acyloxy, sulfonyl, sulfonyl halide, sulfonyl ester, carboxyl,
carboxylic acid, hydroxyalkyl, alkyl halide, alkyl amine, alkyl
amide, substituted alkyl amine, or alkyl amide. In certain
embodiments, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6,
and R.sup.7 may be chosen from hydrogen, alkyl, aryl, alkylaryl,
substituted alkyl, substituted aryl, and substituted alkylaryl. In
various aspects, one or more of R.sup.2, R.sup.3, R.sup.4, R.sup.5,
R.sup.6, and R.sup.7 may be hydrogen. In an exemplary embodiment,
each of R.sup.2, R.sup.3, R.sup.4, and R.sup.5 is hydrogen.
[0076] In some embodiments, R.sup.2 and R.sup.3 are independently
chosen from hydrocarbyl, substituted hydrocarbyl, and hydrogen. In
some embodiments, R.sup.2 and R.sup.3 are lower chain alkyl groups
including methyl, ethyl, propyl, butyl, pentyl, and hexyl. In
another embodiment R.sup.2 and R.sup.3 are phenyl, benzyl, or
substituted phenyl or benzyl. In preferred embodiments, R.sup.2 is
hydrogen and R.sup.3 is chosen from hydrogen, methyl, ethyl,
phenyl, and benzyl. In one embodiment, R.sup.2 and R.sup.3 are
hydrogen.
[0077] R.sup.4 and R.sup.5 are independently chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl. In some embodiments,
(CR.sup.4R.sup.5).sub.n constitutes a hydrocarbyl chain, which may
be linear or branched, with n representing the number of linked
carbon atoms in the chain. In various embodiments, n is equal to or
greater than 1. In some embodiments, n ranges from 1 to 20 and the
hydrocarbyl chain comprises from 1 to 20 linked carbon atoms. In
still another embodiment, n is equal to 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. In exemplary
embodiments, n is 1 or 2. In some embodiments, R.sup.4 and R.sup.5
may be hydrogen throughout the chain, in other aspects R.sup.4 and
R.sup.5 are hydrocarbyl or substituted hydrocarbyl throughout the
chain.
[0078] R.sup.6 may be chosen from hydrogen, hydrocarbyl,
substituted hydrocarbyl. Where R.sup.6 is a hydrocarbyl, it may be
any alkyl chain but is preferably a lower chain alkyl group such as
methyl, ethyl, propyl, butyl, pentyl, or hexyl. The lower alkyl
groups may additionally be branched or cyclic. Non-limiting
examples include isopropyl, isobutyl, sec-butyl, t-butyl,
cyclopropyl, cyclobutyl, cyclopentyl, and the like. In another
embodiment, R.sup.6 is phenyl, benzyl, or substituted phenyl or
benzyl. In an exemplary embodiment, R.sup.6 is methyl.
[0079] R.sup.7 may be optionally present in the compound comprising
Formula (I). When present, R.sup.7 is chosen from hydrocarbyl,
substituted hydrocarbyl, and hydrogen. Where R.sup.7 is a
hydrocarbyl, it may be any alkyl group but is preferably a lower
chain alkyl group such as methyl, ethyl, propyl, butyl, pentyl, or
hexyl. The lower alkyl groups may additionally be branched or
cyclic, non-limiting examples include isopropyl, isobutyl,
sec-butyl, t-butyl, cyclopropyl, cyclobutyl, cyclopentyl, and the
like. In another embodiment, R.sup.7 may be phenyl, benzyl, or
substituted phenyl or benzyl. In a further embodiment, R.sup.7 may
be hydrogen.
[0080] The compounds comprising Formula (I) also contain a
heteroatom (Z). In some embodiments, Z is nitrogen, selenium, or
sulfur atom, including sulfoxide and sulfone groups. The nitrogen,
selenium, or sulfur atoms may be charged and/or be present in
various oxidation states within the molecule. Where the Z carries a
charge, the compound may further comprise a counterion including,
but not limited to lithium, sodium, potassium, calcium, magnesium,
and the like.
[0081] In certain embodiments, when Z is sulfur and n is 1, then
R.sup.1 and R.sup.3 are other than hydrogen. In other embodiments,
when Z is nitrogen, n is from 2 to 4, and R.sup.3 is hydrogen, then
R.sup.1 is other than hydrogen or methyl.
[0082] In some embodiments, R.sup.1 comprises
(CR.sup.8R.sup.9).sub.mYR.sup.10R.sup.11 and the compound comprises
Formula (Ia):
##STR00010##
[0083] wherein: [0084] R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6,
R.sup.7, X.sup.1, X.sup.2, Z, and n are as described above for the
compound comprising Formula (I); [0085] R.sup.8, R.sup.9, and
R.sup.10 are independently chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0086] R.sup.11 is optionally present,
when present it is chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0087] Y is chosen from nitrogen, sulfur,
sulfone, sulfoxide, and selenium; and [0088] m is an integer
.gtoreq.1.
[0089] Each of R.sup.8, R.sup.9, R.sup.10, and R.sup.11 may be
chosen from hydrogen, hydrocarbyl, and substituted hydrocarbyl. The
hydrocarbyl may be, without limit, alkyl, cycloalkyl, alkenyl,
alkenoxy, aryl, or alkylaryl. The substituted hydrocarbyl may be,
without limit, arylalkoxyl, alkoxy, alkoxycarbonyl, carbonyl, acyl,
acyloxy, sulfonyl, sulfonyl halide, sulfonyl ester, carboxyl,
carboxylic acid, hydroxyalkyl, alkyl halide, alkyl amine, alkyl
amide, substituted alkyl amine, or alkyl amide. In certain
embodiments, each of R.sup.8, R.sup.9, R.sup.10, and R.sup.11 may
be chosen from hydrogen, alkyl, aryl, alkylaryl, substituted alkyl,
substituted aryl, and substituted alkylaryl. In various aspects,
one or more of R.sup.8, R.sup.9, R.sup.10, and R.sup.11 may be
hydrogen. In an exemplary embodiment, R.sup.3, R.sup.8, and R.sup.9
are hydrogen.
[0090] Where R.sup.10 is a hydrocarbyl, it may be any alkyl chain
but is preferably a lower chain alkyl group such as methyl, ethyl,
propyl, butyl, pentyl, or hexyl. The lower alkyl groups may
additionally be branched or cyclic. Non-limiting examples include
isopropyl, isobutyl, sec-butyl, t-butyl, cyclopropyl, cyclobutyl,
cyclopentyl, and the like. In another embodiment, R.sup.10 is
phenyl, benzyl, or substituted phenyl or benzyl. In an exemplary
embodiment, R.sup.10 is methyl.
[0091] R.sup.11 may be optionally present in the compound
comprising Formula (Ia). When present, R.sup.11 is chosen from
hydrocarbyl, substituted hydrocarbyl, and hydrogen. Where R.sup.11
is hydrocarbyl, it may be any alkyl group but is preferably a lower
chain alkyl group such as methyl, ethyl, propyl, butyl, pentyl, or
hexyl. The lower alkyl groups may additionally be branched or
cyclic, non-limiting examples include isopropyl, isobutyl,
sec-butyl, t-butyl, cyclopropyl, cyclobutyl, cyclopentyl, and the
like. In another embodiment, R.sup.11 may be phenyl, benzyl, or
substituted phenyl or benzyl. In a further embodiment, R.sup.11 may
be hydrogen.
[0092] In some embodiments, (CR.sup.8R.sup.9).sub.m constitutes a
hydrocarbyl chain, which may be linear or branched, with m
representing the number of linked carbon atoms in the chain. In
various embodiments, m is equal to or greater than 1. In some
embodiments, m ranges from 1 to 20 and the hydrocarbyl chain
comprises from 1 to 20 linked carbon atoms. In still another
embodiment, m is equal to 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
14, 15, 16, 17, 18, 19, or 20. In exemplary embodiments, m is 1 or
2. In some embodiments, R.sup.8 and R.sup.9 may be hydrogen
throughout the chain, in other aspects R.sup.8 and R.sup.9 are
hydrocarbyl or substituted hydrocarbyl throughout the chain.
[0093] The compounds comprising Formula (Ia) also contain a
heteroatom (Y). In some embodiments, Y is nitrogen, selenium, or
sulfur atom, including sulfoxide and sulfone groups. The nitrogen,
selenium, or sulfur atoms may be charged and/or be present in
various oxidation states within the molecule. Where the Y carries a
charge, the compound may further comprise a counterion including,
but not limited to lithium, sodium, potassium, calcium, magnesium,
and the like.
[0094] In one embodiment, R.sup.2, R.sup.3, R.sup.4, R.sup.5,
R.sup.8 and R.sup.9 are hydrogen, n and m independently range from
1 to 10; Z and Y are independently chosen from sulfur, sulfone,
sulfoxide, and selenium. In some iterations, R.sup.6 and R.sup.10
are lower chain alkyl, and R.sup.7 and R.sup.11, if present, are
independently hydrogen or lower chain alkyl.
[0095] Non-limiting compounds comprising Formula (I) or Formula
(Ia) are listed in Table 1.
TABLE-US-00001 TABLE 1 Exemplary compounds comprising Formulas (I)
or (IIa). # X.sup.1 X.sup.2 Z n R.sup.1 R.sup.3 R.sup.4 R.sup.5
R.sup.6 R.sup.7 1 N O S 1 (CH.sub.2).sub.2SCH.sub.3 H H H CH.sub.3
-- 2 N O S 1 CH.sub.2SCH3 H H H CH.sub.2CH.sub.3 -- 3 N O S 2
CH.sub.3 H H H CH.sub.3 CH.sub.3 4 N O S 2 CH.sub.2Ph H H H
CH.sub.2CH.sub.3 CH.sub.3 5 N O SO 1 CH.sub.3 H H H CH.sub.3 -- 6 N
O SO 1 (CH.sub.2).sub.2SCH.sub.3 H H H CH.sub.3 -- 7 N O SO 2
(CH.sub.2).sub.2SOCH.sub.3 H H H CH.sub.3 -- 8 N O SO 2
(CH.sub.2).sub.2SeCH.sub.3 H H H CH.sub.2CH.sub.3 -- 9 N O SO.sub.2
1 CH.sub.2Ph H H H CH.sub.2CH.sub.3 -- 10 N O SO.sub.2 1 CH.sub.3 H
H H CH.sub.3 -- 11 N O SO.sub.2 2 (CH.sub.2).sub.2SCH.sub.3 H H H
Ph -- 12 N O SO.sub.2 2 (CH.sub.2).sub.2SOCH.sub.3 H H H
CH.sub.2CH.sub.3 -- 13 N O SO.sub.2 2 (CH.sub.2).sub.2SOCH.sub.3 H
H H CH.sub.3 14 N O SO.sub.2 2 (CH.sub.2).sub.2SO.sub.2CH.sub.3 H H
H CH.sub.3 -- 15 N O SO 2 (CH.sub.2).sub.2SO.sub.2CH.sub.3 H H H
CH.sub.3 -- 16 N O N 1 (CH.sub.2).sub.2N(CH.sub.3)CH.sub.2 CH.sub.3
H H H CH.sub.2CH.sub.3 CH.sub.3 17 N O Se 1 CH.sub.2SeCH.sub.3 H H
H CH.sub.3 -- 18 N O Se 2 (CH.sub.2).sub.2SeCH.sub.3 H H H CH.sub.3
-- 19 O N S 1 (CH.sub.2).sub.2SCH.sub.3 H H H CH.sub.3 -- 20 O N S
1 CH.sub.2SCH3 H H H CH.sub.2CH.sub.3 -- 21 O N S 2 CH.sub.3 H H H
CH.sub.3 CH.sub.3 22 O N S 2 CH.sub.2Ph H H H CH.sub.2CH.sub.3
CH.sub.3 23 O N SO 1 CH.sub.3 H H H CH.sub.3 -- 24 O N SO 1
(CH.sub.2).sub.2SCH.sub.3 H H H CH.sub.3 -- 25 O N SO 2
(CH.sub.2).sub.2SO.sub.2CH.sub.3 H H H CH.sub.3 -- 26 O N SO 2
(CH.sub.2).sub.2SeCH.sub.3 H H H CH.sub.2CH.sub.3 -- 27 O N
SO.sub.2 1 CH.sub.2Ph H H H CH.sub.2CH.sub.3 -- 28 O N SO.sub.2 1
CH.sub.3 H H H CH.sub.3 -- 29 O N SO.sub.2 2
(CH.sub.2).sub.2SCH.sub.3 H H H CH.sub.3 -- 30 O N SO.sub.2 2
(CH.sub.2).sub.2SOCH.sub.3 H H H CH.sub.2CH.sub.3 -- 31 O N
SO.sub.2 2 (CH.sub.2).sub.2SOCH.sub.3 H H H CH.sub.3 32 O N
SO.sub.2 2 (CH.sub.2).sub.2SO.sub.2CH.sub.3 H H H CH.sub.3 33 O N N
1 (CH.sub.2).sub.2N(CH.sub.3)CH.sub.2 CH.sub.3 H H H
CH.sub.2CH.sub.3 CH.sub.3 34 O N Se 1 CH.sub.2SeCH.sub.3 H H H
CH.sub.3 -- 35 O N Se 2 (CH.sub.2).sub.2SeCH.sub.3 H H H CH.sub.3
-- 36 O O S 1 (CH.sub.2).sub.2SCH.sub.3 H H H Ph -- 37 O O S 1
CH.sub.2SCH3 H H H CH.sub.2CH.sub.3 -- 38 O O S 2 CH.sub.3 H H H
CH.sub.3 CH.sub.3 39 O O S 2 CH.sub.2Ph H H H CH.sub.2CH.sub.3
CH.sub.3 40 O O SO 1 CH.sub.3 H H H CH.sub.3 -- 41 O O SO 1
(CH.sub.2).sub.2SCH.sub.3 H H H CH.sub.3 -- 42 O O SO 2
(CH.sub.2).sub.2SO.sub.2CH.sub.3 H H H CH.sub.3 43 O O SO 2
(CH.sub.2).sub.2SOCH.sub.3 H H H CH.sub.3 -- 44 O O SO 2
(CH.sub.2).sub.2SeCH.sub.3 H H H CH.sub.2CH.sub.3 -- 45 O O SO 2
(CH.sub.2).sub.2SOCH.sub.3 H H H CH.sub.3 46 O O SO.sub.2 1
CH.sub.2Ph H H H CH.sub.2CH.sub.3 -- 47 O O SO.sub.2 1 CH.sub.3 H H
H CH.sub.3 -- 48 O O SO.sub.2 2 (CH.sub.2).sub.2SCH.sub.3 H H H
CH.sub.3 -- 49 O O SO.sub.2 2 (CH.sub.2).sub.2SOCH.sub.3 H H H
CH.sub.2CH.sub.3 -- 50 O O SO.sub.2 2
(CH.sub.2).sub.2SO.sub.2CH.sub.3 H H H CH.sub.3 51 O O N 1
(CH.sub.2).sub.2NCH.sub.3CH.sub.2CH.sub.3 H H H CH.sub.2CH.sub.3
CH.sub.3 52 O O Se 1 CH.sub.2SeCH.sub.3 H H H Ph -- 53 O O Se 2
(CH.sub.2).sub.2SeCH.sub.3 H H H CH.sub.3 -- 54 ##STR00011## 55
##STR00012## 56 ##STR00013## 57 ##STR00014##
[0096] In an alternative embodiment, the compound comprises Formula
(II):
##STR00015##
[0097] wherein, [0098] R.sup.1, R.sup.2, R.sup.3, R.sup.4, and
R.sup.5 are independently chosen from hydrogen, hydrocarbyl and
substituted hydrocarbyl; [0099] R.sup.6 is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0100] R.sup.7 is
optionally present, when present it is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0101] Z is chosen from
nitrogen, sulfur, sulfone, sulfoxide, and selenium; and [0102] n is
an integer .gtoreq.1; [0103] provided that when Z is sulfur and n
is 1, then R.sup.1 and R.sup.3 are other than hydrogen; and when Z
is nitrogen, n is 2 or 4, and R.sup.3 is hydrogen, then R.sup.1 is
other than methyl.
[0104] Each of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5,
R.sup.6, R.sup.7, Z, and n may be chosen as described for Formula
(I). In some embodiments of the compound comprising Formula (II),
when Z is nitrogen, then either both R.sup.1 and R.sup.3 are methyl
or neither R.sup.1 nor R.sup.3 is methyl. In another embodiment in
which Z is sulfur, then R.sup.6 is not hydrogen or benzyl. In yet
another embodiment in which Z is sulfur and n is 1, then R.sup.6 is
not hydrogen, benzyl, or paramethoxybenzyl.
[0105] In one embodiment, the compound comprises Formula (IIb):
##STR00016##
[0106] wherein; [0107] R.sup.1 and R.sup.6 are independently chosen
from hydrogen, alkyl, aryl, alkylaryl, substituted alkyl,
substituted aryl, and substituted alkylaryl.
[0108] In some embodiments, R.sup.1 is chosen from methyl, ethyl,
phenyl, and benzyl; and R.sup.6 is chosen from hydrogen, methyl,
and ethyl. In an exemplary embodiment, both R.sup.1 and R.sup.6 are
methyl, as in the compound comprising Formula (IIc):
##STR00017##
[0109] The atoms at the 3- and 6-positions of the ring of the
compound comprising Formula (IIb) or Formula (IIc) may have a
configuration chosen from RR, RS, SR, and SS, respectively.
[0110] In additional embodiments, R.sup.1 of the compound
comprising Formula (II) comprises
(CR.sup.8R.sup.9).sub.mYR.sup.10R.sup.11 such that the compound
comprises Formula (IIa):
##STR00018##
[0111] wherein: [0112] R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6,
R.sup.7, Z, and n are as described above for the compounds
comprising Formula (II); [0113] R.sup.8, R.sup.9, and R.sup.10 are
independently chosen from hydrogen, hydrocarbyl, and substituted
hydrocarbyl; [0114] R.sup.11 is optionally present, when present it
is chosen from hydrogen, hydrocarbyl, and substituted hydrocarbyl;
[0115] Y is chosen from nitrogen, sulfur, sulfone, sulfoxide, and
selenium; and [0116] m is an integer .gtoreq.1.
[0117] Each of R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6,
R.sup.7, Z, and n may be chosen as described for compounds
comprising Formula (I), and each of R.sup.8, R.sup.9, R.sup.10,
R.sup.11, Y, and m may be chosen as described for compounds
comprising Formula (Ia).
[0118] In some embodiments of the compound comprising Formula
(IIa), the two pendant groups do not comprise a lysine or lysine
derivative. In some embodiments, when Z and Y are nitrogen, and n
and m are 4 or 5, then R.sup.6 and R.sup.10 are not hydrogen or
COOR.sup.8, and R.sup.8 and R.sup.11 are chosen from hydrogen,
benzyl, and t-butyl.
[0119] In various embodiments, R.sup.2, R.sup.3, R.sup.4, R.sup.5,
R.sup.8 and R.sup.9 are hydrogen, n and m independently range from
1 to 10; Z and Y are independently chosen from sulfur, sulfone,
sulfoxide, and selenium. In some iterations, R.sup.6 and R.sup.10
are lower chain alkyl, and R.sup.7 and R.sup.11, if present, are
independently hydrogen or lower chain alkyl. In an exemplary
embodiment, each of R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.8 and
R.sup.9 are hydrogen, both n and m are 2, both Z and Y are sulfur,
both R.sup.6 and R.sup.10 are methyl, and neither R.sup.7 nor
R.sup.11 are present.
[0120] Non-limiting examples of compounds comprising Formula (II)
or Formula (IIa) are shown in Table 2.
TABLE-US-00002 TABLE 2 Exemplary compounds comprising Formulas (II)
or (IIa). 1 ##STR00019## 2 ##STR00020## 3 ##STR00021## 4
##STR00022## 5 ##STR00023## 6 ##STR00024## 7 ##STR00025## 8
##STR00026## 9 ##STR00027## 10 ##STR00028## 11 ##STR00029## 12
##STR00030## 13 ##STR00031## 14 ##STR00032## 15 ##STR00033## 16
##STR00034## 17 ##STR00035## 18 ##STR00036## 19 ##STR00037## 20
##STR00038## 21 ##STR00039## 22 ##STR00040## 23 ##STR00041## 24
##STR00042## 25 ##STR00043## 26 ##STR00044## 27 ##STR00045## 28
##STR00046## 29 ##STR00047## 30 ##STR00048##
[0121] In still other embodiments, the compound comprises Formula
(III):
##STR00049##
[0122] wherein, [0123] R.sup.1, R.sup.2, R.sup.3, R.sup.4, and
R.sup.5 are independently chosen from hydrogen, hydrocarbyl and
substituted hydrocarbyl; [0124] R.sup.6 is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0125] R.sup.7 is
optionally present, when present it is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0126] Z is chosen from
nitrogen, sulfur, sulfone, sulfoxide, and selenium; and [0127] n is
an integer to 1.
[0128] Each of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5,
R.sup.6, R.sup.7, Z, and n may be chosen as described for Formula
(I).
[0129] In some embodiments, R.sup.1 of the compound comprising
Formula (III) comprises (CR.sup.8R.sup.9).sub.mYR.sup.10R.sup.11
and the compound comprises Formula (IIIa):
##STR00050##
[0130] wherein: [0131] R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6,
R.sup.7, Z, and n are as described above for the compound
comprising Formula (III); [0132] R.sup.8, R.sup.9, and R.sup.10 are
independently chosen from hydrogen, hydrocarbyl, and substituted
hydrocarbyl; [0133] R.sup.11 is optionally present, when present it
is chosen from hydrogen, hydrocarbyl, and substituted hydrocarbyl;
[0134] Y is chosen from nitrogen, sulfur, sulfone, sulfoxide, and
selenium; and [0135] m is an integer .gtoreq.1.
[0136] Each of R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6,
R.sup.7, Z, and n may be chosen as described for compounds
comprising Formula (I), and each of R.sup.8, R.sup.9, R.sup.10,
R.sup.11, Y, and m may be chosen as described for compounds
comprising Formula (Ia).
[0137] In various embodiments, R.sup.2, R.sup.3, R.sup.4, R.sup.5,
R.sup.8 and R.sup.9 are hydrogen, n and m independently range from
1 to 10; Z and Y are independently chosen from sulfur, sulfone,
sulfoxide, and selenium. In some iterations, R.sup.6 and R.sup.10
are lower chain alkyl, and R.sup.7 and R.sup.11, if present, are
independently hydrogen or lower chain alkyl.
[0138] Non-limiting compounds comprising Formula (III) or Formula
(IIIa) are presented in Table 3.
TABLE-US-00003 TABLE 3 Exemplary compounds comprising Formulas
(III) or (IIIa). 1 ##STR00051## 2 ##STR00052## 3 ##STR00053## 4
##STR00054## 5 ##STR00055## 6 ##STR00056## 7 ##STR00057## 8
##STR00058## 9 ##STR00059## 10 ##STR00060## 11 ##STR00061## 12
##STR00062## 13 ##STR00063## 14 ##STR00064## 15 ##STR00065## 16
##STR00066## 17 ##STR00067## 18 ##STR00068## 19 ##STR00069## 20
##STR00070## 21 ##STR00071## 22 ##STR00072## 23 ##STR00073## 24
##STR00074## 25 ##STR00075## 26 ##STR00076## 27 ##STR00077## 28
##STR00078## 29 ##STR00079## 30 ##STR00080##
[0139] Yet another embodiment provides a compound comprising
Formula (IV):
##STR00081##
[0140] wherein, [0141] R.sup.6 and R.sup.10 are independently
chosen from hydrogen, hydrocarbyl, and substituted hydrocarbyl;
[0142] R.sup.7 and R.sup.11 are optionally present, when present
each is independently chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0143] Z and Y are independently chosen
from sulfone, sulfoxide, and selenium; and [0144] n and m are
integers .gtoreq.1; [0145] provided that when Z and Y are
sulfoxide, then R.sup.6 and R.sup.10 are other than methyl.
[0146] Each of R.sup.6, R.sup.7, R.sup.10, R.sup.11, Y, Z, n, and m
may be chosen as described above for compounds comprising Formulas
(I) and (Ia).
[0147] In one embodiment of the compound comprising Formula (IV), Y
and Z are selenium, R.sup.6 and R.sup.10 are lower alkyl, and
R.sup.7 and R.sup.11 are not present. In another embodiment, Y and
Z are selenium, R.sup.6 and R.sup.10 are methyl, and R.sup.7 and
R.sup.11 are not present. Table 4 lists non-limiting examples of
compounds comprising Formula (IV).
TABLE-US-00004 TABLE 4 Exemplary compounds comprising Formula (IV).
1 ##STR00082## 2 ##STR00083## 3 ##STR00084## 4 ##STR00085## 5
##STR00086## 6 ##STR00087## 7 ##STR00088## 8 ##STR00089## 9
##STR00090## 10 ##STR00091##
[0148] In exemplary embodiments, the compound of the invention
comprises Formula (V):
##STR00092##
TABLE-US-00005 TABLE 5 Exemplary compounds comprising Formula (V).
1 ##STR00093## 2 ##STR00094## 3 ##STR00095## 4 ##STR00096##
[0149] In some aspects of the invention, the compounds comprise one
or more chiral centers. Each chiral center of the compounds
comprising Formulas (I), (II), (III), (IV), and (V) may have an R
or an S configuration. In some embodiments, where the carbon atom
at the 3-position and the 6-position has four different
substituents, the positions are chiral centers. In such
embodiments, the configurations at the 3- and 6-positions may be
chosen from RR, RS, SR, and SS, respectively. In another aspect,
compositions may be mixtures of two or more isomers. In another
aspect, the compositions may be optically pure or enriched with one
or more isomers. In aspects of the invention where the pendent
groups at the 3- and 6-positions are the same, the compounds may
comprise the D-isomer, the L-isomer, or the meso isomer. In another
embodiment, the composition may be a mixture of two or more of the
D-isomer, the L-isomer, and the meso isomer.
[0150] The compounds of the invention may also be provided as
substantially pure compounds. In some aspects, the compounds are
substantially pure in mixtures of stereoisomers that are
substantially free from byproducts including monomers, non-cyclic
dimers, or other oligomers. In another aspect, the compounds
described herein may be provided as a substantially pure enantiomer
or diastereomer. By substantially pure, it is meant that the
desired compound is present in about 80% purity, about 90% purity,
or about 95% purity, about 99% purity, about 99.5% purity, about
99.9% purity, 99.99% purity, or higher. In another embodiment, the
compounds may be provided as optically pure compounds, optically
pure compounds may have about 80%, about 90%, about 99% optical
purity, about 99.9%, or about 99.99% optical purity, or higher.
[0151] The compounds provided in this section may have a variety of
uses and purposes, in their cyclic forms or as polymers (see
below). The compounds or compositions comprising the compounds
provided herein may have one set of properties under one set of
conditions and different properties under different conditions. In
some embodiments, the compounds provided herein may be stable in
aqueous solutions under approximately neutral pH. In other
embodiments, the compounds provided herein may hydrolyze in aqueous
solutions at pH values of less than about 6.0, less than about 5.0,
less than about 3.0, less than about 2.0, or less than about
1.0.
(II) Processes for Preparing Cyclic Dimers
[0152] Still another aspect of the present disclosure encompasses
processes for the preparation of the compounds disclosed herein. In
particular, processes for the preparation of the cyclic dimers
comprise contacting alpha acids under conditions such that the
alpha acids form cyclic dimers.
(a) Preparation of Compounds Comprising Formula
(IX)--Condensation
[0153] In one aspect, the process for producing a compound
comprising Formula (IX) comprises (a) contacting a compound
comprising Formula (VI) with a compound comprising Formula (VII) or
a compound comprising Formula (VIII) and an acid catalyst and (b)
dehydrating the resulting reaction mixture to form the compound
comprising Formula (IX). The compounds comprising Formula (IX),
(VI), (VII), and (VIII) have the following structures:
##STR00097##
[0154] wherein, [0155] X.sup.1 is chosen from oxygen and nitrogen,
[0156] R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are
independently chosen from hydrogen, hydrocarbyl, and substituted
hydrocarbyl; [0157] R.sup.6 is chosen from hydrogen, hydrocarbyl,
and substituted hydrocarbyl; [0158] R.sup.7 is optionally present,
when present it is chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0159] Z is chosen from nitrogen, sulfur,
sulfone, sulfoxide, and selenium; and [0160] n is an integer
.gtoreq.1.
[0161] R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6,
R.sup.7, Z, and n may be chosen as described above for the compound
comprising Formula (I) in section (I). In some embodiments, R.sup.1
may be (CR.sup.8R.sup.9).sub.mYR.sup.10R.sup.11, wherein R.sup.8,
R.sup.9, R.sup.10, R.sup.11, Y, and m may be chosen as described
for compounds comprising Formula (Ia) in section (I).
[0162] In some embodiments, the process proceeds according to
Reaction Scheme 1(a) to form the compound comprising Formula
(II):
##STR00098##
[0163] wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5,
R.sup.6, R.sup.7, Z, and n are as defined above.
[0164] In still other embodiments, the reaction proceeds according
to Reaction Scheme 1(b) to form the compound comprising Formula
(III):
##STR00099##
[0165] wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5,
R.sup.6, R.sup.7, Z, and n are as defined above.
[0166] The compound comprising Formula (VII) may be an amino acid.
Non-limiting examples of suitable amino acids include glycine,
alanine, valine, leucine, isoleucine, phenylalanine, serine,
threonine, lysine, .DELTA.-hydroxylysine, ornithine, aspartic acid,
glutamic acid, cysteine, cystine, methionine, selenomethionine,
tyrosine, thyroxine, proline, hydroxyproline, and tryptophan. In
some aspects, the amino acid does not require protection. In other
aspects, the amino acid may be protected, for example on the side
chain side chain or at the N-terminus by means known in the
art.
[0167] The process comprises contacting the compound comprising
Formula (VI) with a compound comprising Formula (VII) or a compound
comprising Formula (VIII). In general, the two compounds are
provided to the reaction in an approximately equal molar ratio. In
some embodiments, the compound comprising Formula (VI) may be
provided in a molar ratio with respect to the compound comprising
Formula (VII) or Formula (VIII) of about 0.1:1, 0.2:1, 0.3:1,
0.4:1, 0.5:1, 0.6:1; 0.7:1, 0.8:1, 0.9:1, 1:1.0, 1:1.1, 1:1.2,
1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:2.0, 1:2.5, 1:3, or
about 1:3.5. In a preferred embodiment, the compound comprising
Formula (VI) is provided in a 1:1 molar ratio with the compound
comprising Formula (VII) or Formula (VIII).
[0168] In some aspects, the reaction may be conducted under
dehydration conditions in the presence of an acid catalyst. In some
embodiments, the starting materials are purified to a low water
concentration prior to the contacting step. For example, the
starting materials comprising the compounds of Formulas (VI) and
(VII) or (VIII) may be provided to the reaction mixture with a
water content below about 5%, below about 3%, below about 2%, or
below about 1%.
[0169] A variety of acid catalysts may be suitable to produce the
compound comprising Formula (IX). In some embodiments, the acid
catalyst may be chosen from organic acids, inorganic acids, and
solid resins. Exemplary acid catalysts include, without limitation,
phosphoric acid, acetic acid, boric acid, hydrochloric acid,
trifluoroacetic acid, methanesulfonic acid, ortho- meta- and
para-toluenesulfonic acid, polyphosphoric acid, sulfuric acid,
tosylic acid, xylenesulfonic acid, Dowex resins, Amberlyst resins,
Zn dust, and Sn based catalysts (such as, for example, Sn dust, tin
oxide, tin (II) chloride, dibutyltin dilaurate, and stannous
octoate), germanium dioxide, antimony trioxide, zinc oxide, iron
(III) oxide, aluminum oxide, silicon dioxide, titanium dioxide,
mixtures and combinations thereof.
[0170] The acid catalyst may be added in a range of ratios to the
compounds comprising Formulas (VI) and (VII) or (VIII). In some
aspects the amount of catalyst added may range from 0.0001 mol % of
the amount of the compounds comprising Formulas (VI) and (VII) or
(VIII) to about 5 mol % of the compounds comprising Formulas (VI)
and (VII) or (VIII). In some embodiments, the acid catalyst is
added in an amount below 5 mol %, below 2 mol %, or below 1 mol %.
More preferably, the acid catalyst is provided in the reaction in a
molar ratio of about 0.001, 0.002, 0.003, 0.004, 0.005, 0.006,
0.007, 0.008, 0.009, or 0.010 mol % to the compound comprising
Formula (VI).
[0171] The reaction may be conducted under dehydration conditions
to promote formation of the cyclic dimer. In certain embodiments,
dehydration may be accomplished via distillation. For example, the
reaction may be subjected to simple distillation, fractional
distillation, azeotropic distillation, steam distillation, vacuum
distillation, distillation using a Dean Stark trap or another
similar trap, azeotropic distillation using a Dean Stark or another
similar trap, and the like. In other embodiments, dehydration may
be accomplished via a drying reagent which may include molecular
sieves, calcium sulfate, magnesium sulfate, sodium sulfate,
potassium hydroxide, potassium carbonate, and the like.
[0172] The temperature at which the reaction takes place may vary
in different embodiments and over the course of the reaction. In
one embodiment, the reaction may be carried out at a temperature
ranging from about 100.degree. C. and about 200.degree. C. In
another embodiment, the reaction may be conducted at a temperature
of about 100.degree. C., 110.degree. C., 120.degree. C.,
130.degree. C., 140.degree. C., 150.degree. C., 160.degree. C.,
170.degree. C., 180.degree. C., 190.degree. C., 200.degree. C., or
at a range between and including any two of these values. In
another embodiment, the temperature may range from about
130.degree. C. and about 150.degree. C. In yet another embodiment,
the temperature may range from about 110.degree. C. and about
120.degree. C. In general, the reaction is conducted at atmospheric
pressure, but in certain embodiments, the reaction may also be
conducted above or below atmospheric pressure.
[0173] The process may be performed in the presence of a solvent or
the reaction may be performed neat. Where the reaction includes a
solvent, the type of solvent may vary depending upon the identities
of the reactants. Thus, the solvent may be a nonpolar solvent, a
protic polar solvent, an aprotic polar solvent, or a combination
thereof. Non-limiting examples of suitable nonpolar solvents
include anisole, benzene, butyl acetate, tert-butyl methyl ether,
chlorobenzene, chloroform, chloromethane, cyclohexane,
dichloromethane, dichloroethane, di-tert-butyl ether, dimethyl
ether, diethylene glycol, diethyl ether, diglyme, diisopropyl
ether, ethyl tert-butyl ether, ethylene oxide, fluorobenzene,
heptane, hexane, methyl tert-butyl ether, toluene, xylene and
combinations thereof. Examples of suitable protic polar solvents
include without limit water, alcohols (e.g., methanol, ethanol,
isopropanol, n-propanol, isobutanol, n-butanol, s-butanol,
t-butanol), diols (e.g., propylene glycol and the like), organic
acids (e.g., formic acid, acetic acid, and so forth), amides (e.g.,
formamide, acetamide, and the like), and combinations of any of the
above. Non-limiting examples of suitable aprotic polar solvents
include acetone, acetonitrile, diethoxymethane,
N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO),
N,N-dimethylpropionamide,
1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU),
1,3-dimethyl-2-imidazolidinone (DMI), 1,2-dimethoxyethane (DME),
dimethoxymethane, bis(2-methoxyethyl)ether, N,N-dimethylacetamide
(DMAC), N-methyl-2-pyrrolidinone (NMP), 1,4-dioxane, ethyl acetate,
ethyl formate, formamide, hexachloroacetone,
hexamethylphosphoramide, methyl acetate, N-methylacetamide,
methylethyl ketone, methylisobutyl ketone, N-methylformamide,
methylene chloride, methoxyethane, morpholine, nitrobenzene,
nitromethane, propionitrile, propyl acetates, sulfolane,
tetramethylurea, tetrahydrofuran (THF), 2-methyl tetrahydrofuran,
tetrahydropyran, trichloromethane, and combinations thereof. In
exemplary embodiments, the solvent is chosen from toluene, xylene,
anisole, and mixtures thereof.
[0174] The weight-to-weight ratio of the solvent to the compounds
comprising Formulas (VI) and (VII) or (VIII) can and will vary.
Typically, the weight-to-weight ratio of the solvent to the
compounds comprising Formulas (VI) and (VII) or (VIII) may range
from about 1:1 to about 100:1. In various embodiments, the
weight-to-weight ratio of the solvent to the compounds comprising
Formulas (VI) and (VII) or (VIII) may range from about 1:1 to 5:1,
from about 5:1 to about 20:1, from about 20:1 to about 40:1, from
about 40:1 to about 80:1, or from about 80:1 to about 100:1. In
some embodiments, the weight-to-weight ratio of the solvent to the
compounds comprising Formulas (VI) and (VII) or (VIII) may be about
30:1, or about 60:1.
[0175] The duration of the reaction can and will vary. In general,
the reaction may be allowed to proceed from several hours to
several days. Typically, however, the reaction is allowed to
proceed for a sufficient period of time until the reaction is
complete, as determined by means well known to those of skill in
the art. In this context, the final reaction mixture contains a
significantly diminished amount of the compounds comprising
Formulas (VI) and (VII) or (VIII) and a significantly increased
amount of the compound comprising Formula (IX) compared to the
amounts of each present at the beginning of the reaction. In some
embodiments, the reaction may be allowed to proceed for a period of
time ranging from about 1 hour to about 10 hours. In another
embodiment, the reaction may be allowed to proceed for a period of
time ranging from about 1 hour to about 5 hours. In a preferred
embodiment, the reaction may be allowed to proceed for a period for
about 3 hours to about 5 hours.
[0176] The yield of the compound comprising Formula (IX) can and
will vary. In general, yield of the compound comprising Formula
(IX) will be at least about 15%, at least about 20%, 30%, at least
about 40%, at least about 50%, at least about 60%, at least about
70%, at least about 80%, or at least about 90%.
[0177] The compound comprising Formula (IX) may be isolated from
the reaction mixture and/or purified by means including by size
exclusion chromatography, high performance liquid chromatography
(HPLC), ion-exchange chromatography, chiral chromatography, other
types of chromatography, precipitation, distillation, or
crystallization.
(b) Preparation of Compounds Comprising Formula
(IX)--Polymerization and Thermal Cracking
[0178] In other embodiments, the compound comprising Formula (IX)
may be prepared by (a) heating a compound comprising Formula (VI)
with a compound comprising Formula (VII) or a compound comprising
Formula (VIII) such that a polymer is formed and then (b) heating
the polymer at an increased temperature and reduced pressure to
form the cyclic dimer compound comprising Formula (IX). The
reactants, i.e., the compounds comprising Formulas (VI), (VII), and
(VIII), are described above in section (II)(a).
[0179] The first step of this process comprises heating the
reactants in the presence or absence of an acid catalyst. Suitable
acid catalysts and suitable amounts are detailed above in section
(II)(a). In some embodiments, the heating step is performed under a
vacuum. The heating step may be performed in the presence of a
solvent, as detailed above, or the heating may be performed in the
absence of a solvent (i.e., neat). Similar to the method detailed
above, the reaction mixture may be heated to and maintained at a
temperature ranging from about 100.degree. C. to about 200.degree.
C. In exemplary embodiments, the reaction mixture may be heated to
about 130.degree. C. to about 160.degree. C. The duration of the
heating step may also vary. In some embodiments, the duration of
the heating step may range from about 2 hours to about 10 hours, or
from about 3 hours to about 5 hours.
[0180] The second step of this process comprises additional heating
at a higher temperature and under reduced pressure (i.e., thermal
cracking). The temperature of the second step may range from about
150.degree. C. to about 250.degree. C. In some embodiments the
temperature of the second step may range 150.degree. C. to about
180.degree. C., from about 180.degree. C. to about 200.degree. C.,
from about 200.degree. C. to about 220.degree. C., or from about
220.degree. C. to about 250.degree. C. In general, the second step
is performed under a vacuum. The pressure of the reaction may be
less than about 10 Torr, less than about 1 Torr, less than about
500 mTorr, or less than about 200 mTorr. In various embodiments,
the pressure of the second step of the reaction may range from
about 200 mTorr to about 500 mTorr, or may range from about 0.5
Torr to about 1 Torr. The duration of the second step of the
process may range from about 1 hour to about 5 hours. In one
embodiment, the duration of the second step of the process may
range from about 2 hours to about 3 hours. During the second step
of the process, the compound comprising Formula (IX) may be
distilled as detailed above in section (II)(a).
[0181] The yield of the compound comprising Formula (IX) prepared
by the polymerization/thermal cracking process can and will vary
depending upon a variety of factors. In various embodiments, the
yield of the compound comprising Formula (IX) in distillates from
the reaction mixture may be at least about 15%, at least about 20%,
at least about 30%, at least about 40%, at least about 50%, at
least about 60%, at least about 70%, at least about 80%, at least
about 90%, at least about 95%, or at least about 99%.
[0182] The compound comprising Formula (IX) may be isolated from
the reaction mixture and/or purified by means including by size
exclusion chromatography, HPLC, ion-exchange chromatography, chiral
chromatography, other types of chromatography, precipitation,
distillation, or crystallization.
(c) Preparation of Compounds Comprising Formula (IV)
[0183] The method for preparing the compound comprising Formula
(IV) comprises contacting a compound comprising Formula (X) and a
compound comprising Formula (XI) according to Reaction Scheme
2:
##STR00100##
[0184] wherein, [0185] R.sup.6 and R.sup.10 are independently
chosen from hydrogen, hydrocarbyl, and substituted hydrocarbyl,
[0186] R.sup.7 and R.sup.11 are optionally present, when present
each is independently chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0187] Y and Z are independently chosen
from sulfone, sulfoxide, and selenium; and [0188] n and m are
integers .gtoreq.1.
[0189] In general, the compound comprising Formula (IV) may be
produced by subjecting compounds comprising Formulas (X) and (XI)
to conditions such that the compounds form a cyclic dimer. R.sup.6,
R.sup.7, R.sup.10, R.sup.11, Y, Z, n and m of the compounds
comprising Formulas (X), (XI), and (IV) may generally be as set out
in Section (I).
[0190] The compounds comprising Formulas (X) and (XI) may be
provided to the reaction in an approximately equal molar ratio. In
some embodiments, the compounds comprising Formulas (X) and (XI)
may be provided in a molar ratio of about 0.1:1, 0.2:1, 0.3:1,
0.4:1, 0.5:1, 0.6:1; 0.7:1, 0.8:1, 0.9:1, 1:1.0, 1:1.1, 1:1.2,
1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:2.0, 1:2.5, 1:3, or
1:3.5. In a preferred embodiment, the compounds comprising Formulas
(X) and (XI) are provided in an equal molar ratio.
[0191] A variety of acid catalysts may be used in the reaction. In
some embodiments, the acid catalyst may be chosen from organic
acids, inorganic acids, and solid resins. Exemplary acid catalysts
include, without limitation, acetic acid, hydrochloric acid,
trifluoroacetic acid, methanesulfonic acid, ortho- meta- and
para-toluenesulfonic acid, sulfuric acid, phosphoric acid,
xylenesulfonic acid, Dowex resins, Amberlyst resins, Zn dust, and
Sn dust.
[0192] The acid catalyst may be added in a range of ratios to the
compounds comprising Formulas (X) and (XI). In some aspects the
amount of catalyst added ranges from about 0.0001 mol % of the
amount of the compounds comprising Formulas (X) and (XI) to about 5
mol % of the compounds comprising Formulas (X) and (XI). In some
embodiments, the acid catalyst may be added in an amount below 5
mol %, below 2 mol %, or below 1 mol %. More preferably, the acid
catalyst may be provided in the reaction in a molar ratio of about
0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, or
0.010 mol % to the compounds comprising Formulas (X) and (XI).
[0193] The temperature at which the reaction takes place may vary
in different embodiments and/or over the course of the reaction. In
some aspects, the reaction may be conducted at a temperature of
100.degree. C., 110.degree. C., 120.degree. C., 130.degree. C.,
140.degree. C., 150.degree. C., 160.degree. C., 170.degree. C.,
180.degree. C., 190.degree. C., 200.degree. C., or at a range
between and including any two of these values. In one embodiment,
the reaction may be carried out at a temperature ranging from about
100.degree. C. and about 200.degree. C. In another embodiment, the
temperature may range from about 130.degree. C. and about
150.degree. C. In general, the reaction is conducted at atmospheric
pressure, but in certain embodiments, the reaction may also be
conducted above or below atmospheric pressure.
[0194] The process may be performed in the presence of a solvent,
while in other aspects the reaction may be performed neat. Where a
solvent is present, the solvent may be chosen, by way of
non-limiting example, from the solvents listed in section (II)(a).
In one embodiment, the solvent is chosen from toluene, xylene,
anisole, and mixtures thereof.
[0195] The weight-to-weight ratio of the solvent to the compounds
comprising Formulas (X) and (XI) can and will vary. Typically, the
weight-to-weight ratio of the solvent to the compounds comprising
Formulas (X) and (XI) may range from about 1:1 to about 100:1. In
various embodiments, the weight-to-weight ratio of the solvent to
the compounds comprising Formulas (X) and (XI) may range from about
1:1 to 5:1, from about 5:1 to about 20:1, from about 20:1 to about
40:1, from about 40:1 to about 80:1, or from about 80:1 to about
100:1
[0196] The duration of the reaction can and will vary. In general,
the reaction may be allowed to proceed from several hours to
several days. Typically, however, the reaction is allowed to
proceed for a sufficient period of time until the reaction is
complete, as determined by means well known to those of skill in
the art. In this context, the final reaction mixture contains a
significantly diminished amount of the compounds comprising
Formulas (X) and (XI) and a significantly increased amount of the
compound comprising Formula (IV) compared to the amounts of each
present at the beginning of the reaction. In some embodiments, the
reaction may be allowed to proceed for a period of time ranging
from about 1 hour to about 10 hours.
[0197] The yield of the compound comprising Formula (IV) can and
will vary. In general, yield of the compound comprising Formula
(IV) will be at least about 15%, at least about 20%, 30%, at least
about 40%, at least about 50%, at least about 60%, at least about
70%, at least about 80%, or at least about 90%.
(d) Preparation of the Compound Comprising Formula (V)
[0198] In one embodiment, a process for producing the compound
comprising Formula (V) is provided, which proceeds according to
Reaction Scheme 3:
##STR00101##
[0199] In exemplary embodiments, the acid catalyst is
p-toluenesulfonic acid. The compound comprising Formula (VIb) is
heated to 110-115.degree. C. in the presence of the acid catalyst
in toluene for 3-5 hours with continuous removal of water using a
Dean Stark trap.
[0200] In some embodiments, the process provides the compound
comprising Formula (V) as a racemic mixture comprising
stereoisomers of the compound comprising Formula (V) (i.e., D-, L-,
and meso isomers; see compounds 2, 3, and 4, respectively, in Table
5). The racemic mixture may be separated into individual
diastereomers of the compound comprising Formula (V). In some
embodiments, the D-, and L-isomers may be first separated from the
meso isomer by methods known in the art including, but not limited
to, recrystallization, distillation, and chromatography. The D- and
L-isomers may then be separated by means known in the art
including, but not limited to, chiral chromatography,
recrystallization, and distillation. In other embodiments, the D-,
L-, and meso isomers may be separated by chiral chromatography (see
Example 4).
(III) Applications
[0201] The cyclic dimer compounds detailed above in section (I) may
be used in a variety of applications. Suitable applications
include, without limit, use as plasticizers, emulsifiers,
additives, processing aids, nutritive agents, antioxidant agents,
antimicrobial agents, anticorrosive agents, and feed additives.
[0202] In some embodiments, the cyclic dimer compounds may be used
as a source of alpha acids. In some embodiments, the compounds
disclosed herein may be used as feed additives or included in feed
compositions or feed premixes. In other embodiments, the compounds
described above in section (I) may be part of a composition
comprising at least one nutritive and/or pharmaceutical agent.
[0203] The compositions comprising the cyclic dimer compounds may
be administered to human or animal subjects. Non-limiting examples
of suitable animal subjects include companion animals such as cats,
dogs, rabbits, horses, and rodents such as gerbils; agricultural
animals such as cows, dairy cows, dairy calves, beef cattle, pigs,
goats, sheep, horses, deer; zoo animals such as primates,
elephants, zebras, large cats, bears, and the like; research
animals such as rabbits, sheep, pigs, dogs, primates, mice, rats
and other rodents; avians, including but not limited to chickens,
ducks, turkeys, ostrich, and emu; and aquatic animals chosen from
fish and crustaceans including, but not limited to, salmon, shrimp,
carp, tilapia, and shell fish. The subject may be monogastric or a
ruminant. When the subject is a ruminant the compounds described in
section (I) may remain substantially intact in the rumen such that
the compound is not broken down in the rumen. Thus, the feed
composition may have an increased digestional efficiency for
ruminant subjects. In some aspects, the compounds described in
section (I) remain substantially intact in the rumen. In other
aspects, the compounds described in section (I) may hydrolyze after
passage through the rumen.
(IV) Compositions Comprising Cyclic Dimers
[0204] In yet another aspect, the present invention provides
compositions comprising at least one cyclic dimer compound detailed
above in section (I). The compositions may further comprise at
least one nutritive and/or pharmaceutical agent.
(a) Feed Compositions
[0205] In some embodiments, the composition may be a feed
composition or a feed premix. The feed composition comprises one or
more of the compounds described in section (I) and at least one
nutritive agent. The nutritive agent may be a hydrolysis product of
the cyclic dimer. The compounds described in section (I) may
hydrolyze after passage from through the stomach or rumen of a
subject. For example, the compounds in section (I) may hydrolyze
under conditions where the compounds are subjected to a pH of about
4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5, 1.0, or 0.5, or any pH between
and including the listed values. A substantially hydrolyzed
composition, as used herein, refers to a solution where greater
than 50% of the compounds in section (I) of the composition are in
a noncyclical form. In some embodiments, substantially hydrolyzed
refers to greater than 60%, or greater than 70%, or greater than
80%, or greater than 90% hydrolyzed.
[0206] In other embodiments, the nutritive agent may be a
carbohydrate source, a fat source, a protein source, an amino acid,
and alpha hydroxy acid, or combinations thereof. Suitable
carbohydrate sources may be chosen from those known in the art and
include, without limitation, alginate, arrowroot, barley, canola,
cassava, corn, corn syrup, cottonseed meal, fructose, glucose,
galactose, grain sorghum, kelp meal, lactose, maize, maltose,
mannose, potatoes, oats, rice, rye, sago, sorbitol, soybeans,
tapioca, wheat, wheat gluten, yam, and combinations thereof.
[0207] The fat source may be an inert fat or a non-inert fat.
Non-limiting examples of non-inert fats include plant derived oils
(e.g., canola oil, corn oil, cottonseed oil, palm oil, peanut oil,
safflower oil, soybean oil, and sunflower oil), fish oils (e.g.,
menhaden oil, anchovy oil, albacore tuna oil, cod liver oil,
herring oil, lake trout oil, mackerel oil, salmon oil, and sardine
oil), animal fats (e.g., poultry fat, beef tallow, butter, pork
lard, and whale blubber), yellow grease (i.e., waste grease from
restaurants and low-grade fats from rendering plants), and
combinations thereof. The non-inert fat source may also be a high
fat product such as fish meal (e.g., menhaden meal, anchovy meal,
herring meal, pollack meal, salmon meal, tuna meal, and whitefish
meal), oilseeds (e.g., canola seeds, cottonseeds, flax seeds,
linseeds, Niger seeds, sesame seeds, soy beans, and sunflower
seeds), or distillers grains (e.g., dried distillers grains and
solubles (DDGS) and wet distillers grains). The fat source may be a
ruminally inert fat. Suitable examples of ruminally inert fats
include calcium salts of palm fatty acids (e.g., MEGALAC.RTM.),
saturated free fatty acids, or hydrogenated tallow (e.g.,
ALIFET.RTM.).
[0208] Suitable protein sources may be animal-derived proteins,
plant-derived proteins, or combinations thereof. In some
embodiments, suitable sources of animal derived protein include
blood meal, bone meal, fish meal, fish processing byproducts, meat
meal, meat and bone meal, poultry by-produce meal, feather meal,
and combinations thereof. In other embodiments, suitable sources of
plant-derived proteins include grains such as corn, oats, soybean,
and the like; grain protein concentrates such as soy protein
concentrate; legumes such as peas, lupine, alfalfa; distiller's
grains; oilseed meals such as canola meal, cottonseed meal,
flaxseed meal, soybean meal, sunflower seed meal; and combinations
thereof.
[0209] In some embodiments, the feed composition/premix may include
one or more alpha acids including amino acids and alpha hydroxy
acids. Suitable examples of amino acids, depending upon the
formulation, include alanine, arginine, asparagines, aspartate,
cysteine, glutamate, glutamine, glycine, histidine, isoleucine,
leucine, lysine, methionine, selenomethionine, phenylalanine,
proline, serine, threonine, tryptophan, tyrosine, and valine. Other
amino acids usable as feed additives include, by way of
non-limiting example, N-acylamino acids, hydroxy homologue
compounds, and physiologically acceptable salts thereof, such as
hydrochlorides, hydrosulfates, ammonium salts, potassium salts,
calcium salts, magnesium salts and sodium salts of amino acids. The
feed compositions may further include an alpha hydroxy acid. In
some aspects the alpha hydroxy acids are alpha hydroxy analogs of
amino acids. In one aspect, the alpha acid is the hydroxy analog of
methionine.
[0210] The feed composition may be formulated as a liquid, an
emulsion, dry pellets, or a powder, and may be mixed with various
other ingredients.
(b) Combinations with Nutritive and/or Pharmaceutical Agents
[0211] In other embodiments, the composition comprises at least one
compound detailed in section (I) in combination with at least one
nutritive and/or pharmaceutical agent. Nutritive agents may
comprise any agent that provides nutritive value when administered
to a subject. Non-limiting examples of nutritive agents include
vitamins, minerals (e.g., organic or inorganic), antioxidants,
organic acids, poly unsaturated fatty acids ("PUFA"), prebiotics,
probiotics, herbs, and pigments.
[0212] Suitable vitamins include vitamin C, vitamin A, vitamin E,
vitamin B12, vitamin K, riboflavin, niacin, vitamin D, vitamin B6,
folic acid, pyridoxine, thiamine, pantothenic acid, and biotin. The
form of the vitamin may include salts of the vitamin, derivatives
of the vitamin, compounds having the same or similar activity of a
vitamin, and metabolites of a vitamin.
[0213] Suitable organic trace mineral may comprise a metal chelate
comprising metal ions and an amino acid ligand. Alternatively, the
organic trace mineral may be a metal salt comprising metal ions and
an amino acid anion. The metal ions may be selected from the group
consisting of zinc ions, copper ions, manganese ions, iron ions,
chromium ions, cobalt ions, magnesium ions, calcium ions, and
combinations thereof. In a preferred embodiment, the metal ions are
zinc ions, manganese ions, and copper ions. The amino acids may be
selected from the group comprising alanine, arginine, asparagine,
aspartic acid, cysteine, glutamine, glutamic acid, glycine,
histidine, isoleucine, leucine, lysine, methionine, phenylalanine,
proline, serine, threonine, tryptophan, tyrosine, and valine, or
their hydroxy analogs. In certain embodiments, the copper and zinc
ions are preferably divalent, i.e., each ion carries a charge of
2+. The molar ratio of amino acids to metal ions in the chelate
molecule may generally vary from 1:1 to 3:1 or higher. Typically, a
metal chelate may comprise a mixture of 1:1, 2:1 and 3:1 species.
Preferably, the molar ratio of amino acids to metal ion in the
chelate molecule may generally vary from 1.5:1 to 2.5:1. In an
aqueous medium, the relative proportions of these species are
determined by the applicable stability constants. Where the number
of ligands equates to the charge on the metal ion, the charge is
typically balanced because the carboxyl moieties of the amino acids
are in deprotonated form. For example, in the chelate species
wherein the metal cation carries a charge of 2+ and the amino acid
to metal ratio is 2:1, each of the hydroxy or amino groups is
understood to be bound by a coordinate covalent bond to the metal
ion. Where the number of ligands exceeds the charge on the metal
ion, e.g., in a 3:1 chelate of a divalent metal ion, the amino
acids in excess of the charge typically may remain in a protonated
state to balance the charge. On the other hand, where the positive
charge on the metal ion exceeds the number of amino acids, the
charge may be balanced by the presence of another anion such as,
for example, chloride, bromide, iodide, bicarbonate, hydrogen
sulfate, dihydrogen phosphate and combinations thereof. Divalent
anions may also be present. In an exemplary embodiment, the metal
chelate comprises 2-hydroxy-4-methylthiobutanoic acid.
[0214] The mineral may also be an inorganic trace mineral. Suitable
inorganic trace minerals include, for example, metal sulfates,
metal oxides, metal carbonates, and metal halides. By way of
non-limiting example, the inorganic trace mineral may be copper
sulfate, copper oxide, copper chloride, or copper carbonate.
Alternatively, the inorganic trace mineral may be manganese
sulfate, manganese chloride, or manganous oxide. In another
embodiment, the inorganic trace mineral may be zinc sulfate, zinc
oxide, zinc chloride, or zinc carbonate. In yet an additional
embodiment, the inorganic trace mineral may be sodium selenite or
sodium selenate.
[0215] Suitable antioxidants include, but are not limited to,
ascorbic acid and its salts, ascorbyl palmitate, ascorbyl stearate,
anoxomer, n-acetylcysteine, benzyl isothiocyanate, m-aminobenzoic
acid, o-aminobenzoic acid, p-aminobenzoic acid (PABA), butylated
hydroxyanisole (BHA), butylated hydroxytoluene (BHT), caffeic acid,
canthaxantin, alpha-carotene, beta-carotene, beta-caraotene,
beta-apo-carotenoic acid, carnosol, carvacrol, catechins, cetyl
gallate, chlorogenic acid, citric acid and its salts, clove
extract, coffee bean extract, p-coumaric acid, 3,4-dihydroxybenzoic
acid, N,N'-diphenyl-p-phenylenediamine (DPPD), dilauryl
thiodipropionate, distearyl thiodipropionate,
2,6-di-tert-butylphenol, dodecyl gallate, edetic acid, ellagic
acid, erythorbic acid, sodium erythorbate, esculetin, esculin,
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline (ethoxyquin), ethyl
gallate, ethyl maltol, ethylenediaminetetraacetic acid (EDTA),
eucalyptus extract, eugenol, ferulic acid, flavonoids (e.g.,
catechin, epicatechin, epicatechin gallate, epigallocatechin (EGC),
epigallocatechin gallate (EGCG), polyphenol
epigallocatechin-3-gallate, flavones (e.g., apigenin, chrysin,
luteolin), flavonols (e.g., datiscetin, myricetin, daemfero),
flavanones, fraxetin, fumaric acid, gallic acid, gentian extract,
gluconic acid, glycine, gum guaiacum, hesperetin,
alpha-hydroxybenzyl phosphinic acid, hydroxycinammic acid,
hydroxyglutaric acid, hydroquinone, n-hydroxysuccinic acid,
hydroxytryrosol, hydroxyurea, rice bran extract, lactic acid and
its salts, lecithin, lecithin citrate; R-alpha-lipoic acid, lutein,
lycopene, malic acid, maltol, 5-methoxy tryptamine, methyl gallate,
monoglyceride citrate; monoisopropyl citrate; morin,
beta-naphthoflavone, nordihydroguaiaretic acid (NDGA), octyl
gallate, oxalic acid, palmityl citrate, phenothiazine,
phosphatidylcholine, phosphoric acid, phosphates, phytic acid,
phytylubichromel, pimento extract, propyl gallate, polyphosphates,
quercetin, trans-resveratrol, rosemary extract, rosmarinic acid,
sage extract, sesamol, silymarin, sinapic acid, succinic acid,
stearyl citrate, syringic acid, tartaric acid, thymol, tocopherols
(i.e., alpha-, beta-, gamma- and delta-tocopherol), tocotrienols
(i.e., alpha-, beta-, gamma- and delta-tocotrienols), tyrosol,
vanilic acid, 2,6-di-tert-butyl-4-hydroxymethylphenol (i.e., lonox
100), 2,4-(tris-3',5'-bi-tert-butyl-4'-hydroxybenzyl)-mesitylene
(i.e., lonox 330), 2,4,5-trihydroxybutyrophenone, ubiquinone,
tertiary butyl hydroquinone (TBHQ), thiodipropionic acid,
trihydroxy butyrophenone, tryptamine, tyramine, uric acid, vitamin
K and derivates, vitamin Q10, wheat germ oil, zeaxanthin, or
combinations thereof.
[0216] A variety of organic acids comprised of carboxylic acids are
suitable. In one embodiment, the organic acid may contain from
about one to about twenty-five carbon atoms. In another embodiment,
the organic acid may have from about three to about twenty-two
carbon atoms. In a further embodiment, the organic acid may contain
from about three to about twelve carbon atoms. In yet another
embodiment, the organic acid may contain from about eight to about
twelve carbon atoms. In still another embodiment, the organic acid
may contain from about two to about six carbon atoms. Suitable
organic acids, by way of non-limiting example, include formic acid,
acetic acid, propionic acid, butanoic acid, benzoic acid, lactic
acid, malic acid, tartaric acid, mandelic acid, citric acid,
fumaric acid, sorbic acid, boric acid, succinic acid, adipic acid,
glycolic acid, cinnamaldehyde, and glutaric acid.
[0217] Salts of organic acids comprising carboxylic acids are also
suitable for certain embodiments. Representative suitable salts
include the ammonium, magnesium, calcium, lithium, sodium,
potassium, selenium, iron, copper, and zinc salts of organic acids.
In one embodiment, the organic acid is an ammonium, magnesium,
calcium, lithium, sodium, potassium, selenium, iron, copper, or
zinc salt of formic acid. In another embodiment, the organic acid
is an ammonium, magnesium, calcium, lithium, sodium, potassium,
selenium, iron, copper, or zinc salt of acetic acid. In yet another
embodiment, the organic acid is an ammonium, magnesium, calcium,
lithium, sodium, potassium, selenium, iron, copper, or zinc salt of
propionic acid. In an additional embodiment, the organic acid is an
ammonium, magnesium, calcium, lithium, sodium, potassium, selenium,
iron, copper, or zinc salt of butanoic acid. In a further
embodiment, the organic acid is an ammonium, magnesium, calcium,
lithium, sodium, potassium, selenium, iron, copper, or zinc salt of
benzoic acid. In still another embodiment, the organic acid is an
ammonium, magnesium, calcium, lithium, sodium, potassium, selenium,
iron, copper, or zinc salt of lactic acid. In yet another
embodiment, the organic acid is an ammonium, magnesium, calcium,
lithium, sodium, potassium, selenium, iron, copper, or zinc salt of
malic acid. In still another embodiment, the organic acid is an
ammonium, magnesium, calcium, lithium, sodium, potassium, selenium,
iron, copper, or zinc salt of tartaric acid. In a further
embodiment, the organic acid is an ammonium, magnesium, calcium,
lithium, sodium, potassium, selenium, iron, copper, or zinc salt of
mandelic acid. In yet another embodiment, the organic acid is an
ammonium, magnesium, calcium, lithium, sodium, potassium, selenium,
iron, copper, or zinc salt of citric acid. In an additional
embodiment, the organic acid is an ammonium, magnesium, calcium,
lithium, sodium, potassium, selenium, iron, copper, or zinc salt of
fumaric acid. In an additional embodiment, the organic acid is an
ammonium, magnesium, calcium, lithium, sodium, potassium, selenium,
iron, copper, or zinc salt of sorbic acid. In another embodiment,
the organic acid is an ammonium, magnesium, calcium, lithium,
sodium, potassium, selenium, iron, copper, or zinc salt of boric
acid. In yet another embodiment, the organic acid is an ammonium,
magnesium, calcium, lithium, sodium, potassium, selenium, iron,
copper, or zinc salt of succinic acid. In another embodiment, the
organic acid is an ammonium, magnesium, calcium, lithium, sodium,
potassium, selenium, iron, copper, or zinc salt of adipic acid. In
yet another embodiment, the organic acid is an ammonium, magnesium,
calcium, lithium, sodium, potassium, selenium, iron, copper, or
zinc salt of glycolic acid. In an additional embodiment, the
organic acid is an ammonium, magnesium, calcium, lithium, sodium,
potassium, selenium, iron, copper, or zinc salt of glutaric
acid.
[0218] Alternatively, the organic acid may be comprised of a
substituted carboxylic acid. A substituted carboxylic acid
generally has the same features as those detailed above for
carboxylic acids, but the hydrocarbyl chain has been modified such
that it is branched, is part of a ring structure, or contains some
other substitution. In one embodiment, the substituted carboxylic
acid may contain one or more additional carboxyl groups. Saturated
dicarboxylic acids include malonic acid, succinic acid, glutaric
acid, and adipic acid, and unsaturated dicarboxylic acids include
maleic acid and fumaric acid. In another embodiment, the
substituted carboxylic acid may contain one or more hydroxy groups.
A substituted carboxylic acid with a hydroxy group on the alpha
carbon, i.e., the carbon adjacent to the carboxyl carbon, is
generally called a .alpha.-hydroxy carboxylic acid. Examples of
suitable .alpha.-hydroxy carboxylic acids include glycolic acid,
lactic acid, malic acid, and tartaric acid. In an alternate
embodiment, the substituted carboxylic acid may contain one or more
carbonyl groups. In yet another embodiment, the substituted
carboxylic acid may contain an amino group on the alpha carbon,
i.e., is an .alpha.-amino acid. In one embodiment, the
.alpha.-amino acid may be one of the twenty standard amino acids or
derivatives thereof. In another embodiment, the .alpha.-amino acid
may be an essential .alpha.-amino acid selected from the group
consisting of arginine, histidine, isoleucine, leucine, lysine,
methionine, phenylalanine, threonine, tryptophan, and valine. Salts
of organic acids comprising substituted carboxylic acids are also
suitable for certain embodiments. Representative suitable salts
include the ammonium, magnesium, calcium, lithium, sodium,
potassium, selenium, iron, copper, and zinc salts of organic acids
comprising substituted carboxylic acids.
[0219] Suitable PUFAs include a long chain fatty acid with at least
18 carbon atoms and at least two carbon-carbon double bonds,
generally in the cis-configuration. In an exemplary embodiment, the
PUFA is an omega fatty acid. The PUFA may be an omega-3 fatty acid
in which the first double bond occurs in the third carbon-carbon
bond from the methyl end of the carbon chain (i.e., opposite the
carboxyl acid group). Suitable examples of omega-3 fatty acids
include all-cis 7,10,13-hexadecatrienoic acid;
all-cis-9,12,15-octadecatrienoic acid (alpha-linolenic acid, ALA);
all-cis-6,9,12,15,-octadecatetraenoic acid (stearidonic acid);
all-cis-8,11,14,17-eicosatetraenoic acid (eicosatetraenoic acid);
all-cis-5,8,11,14,17-eicosapentaenoic acid (eicosapentaenoic acid,
EPA); all-cis-7,10,13,16,19-docosapentaenoic acid (clupanodonic
acid, DPA); all-cis-4,7,10,13,16,19-docosahexaenoic acid
(docosahexaenoic acid, DHA);
all-cis-4,7,10,13,16,19-docosahexaenoic acid; and
all-cis-6,9,12,15,18,21-tetracosenoic acid (nisinic acid). In an
alternative embodiment, the PUFA may be an omega-6 fatty acid in
which the first double bond occurs in the sixth carbon-carbon bond
from the methyl end of the carbon chain. Examples of omega-6 fatty
acids include all-cis-9,12-octadecadienoic acid (linoleic acid);
all-cis-6,9,12-octadecatrienoic acid (gamma-linolenic acid, GLA);
all-cis-11,14-eicosadienoic acid (eicosadienoic acid);
all-cis-8,11,14-eicosatrienoic acid (dihomo-gamma-linolenic acid,
DGLA); all-cis-5,8,11,14-eicosatetraenoic acid (arachidonic acid,
AA); all-cis-13,16-docosadienoic acid (docosadienoic acid);
all-cis-7,10,13,16-docosatetraenoic acid (adrenic acid); and
all-cis-4,7,10,13,16-docosapentaenoic acid (docosapentaenoic acid).
In yet another alternative embodiment, the PUFA may be an omega-9
fatty acid in which the first double bond occurs in the ninth
carbon-carbon bond from the methyl end of the carbon chain, or a
conjugated fatty acid, in which at least one pair of double bonds
are separated by only one single bond. Suitable examples of omega-9
fatty acids include cis-9-octadecenoic acid (oleic acid);
cis-11-eicosenoic acid (eicosenoic acid);
all-cis-5,8,11-eicosatrienoic acid (mead acid); cis-13-docosenoic
acid (erucic acid), and cis-15-tetracosenoic acid (nervonic acid).
Examples of conjugated fatty acids include
9Z,11E-octadeca-9,11-dienoic acid (rumenic acid);
10E,12Z-octadeca-9,11-dienoic acid; 8E,10E,12Z-octadecatrienoic
acid (.alpha.-calendic acid); 8E,10E,12E-octadecatrienoic acid
(3-Calendic acid); 8E,10Z,12E-octadecatrienoic acid (jacaric acid);
9E,11E,13Z-octadeca-9,11,13-trienoic acid (.alpha.-eleostearic
acid); 9E,11E,13E-octadeca-9,11,13-trienoic acid (3-eleostearic
acid); 9Z,11Z,13E-octadeca-9,11,13-trienoic acid (catalpic acid),
and 9E,11Z,13E-octadeca-9,11,13-trienoic acid (punicic acid).
[0220] Probiotics and prebiotics may include yeast and bacteria
that help establish an immune protective rumen or gut microflora as
well as small oligosaccharides. By way of non-limiting example,
yeast-derived probiotics and prebiotics include yeast cell wall
derived components such as .beta.-glucans, arabinoxylan isomaltose,
agarooligosaccharides, lactosucrose, cyclodextrins, lactose,
fructooligosaccharides, laminariheptaose, lactulose,
.beta.-galactooligosaccharides, mannanoligosaccharides, raffinose,
stachyose, oligofructose, glucosyl sucrose, sucrose thermal
oligosaccharide, isomalturose, caramel, inulin, and
xylooligosaccharides. In an exemplary embodiment, the yeast-derived
agent may be .beta.-glucans and/or mannanoligosaccharides. Sources
for yeast cell wall derived components include Saccharomyces
bisporus, Saccharomyces boulardii, Saccharomyces cerevisiae,
Saccharomyces capsularis, Saccharomyces delbrueckii, Saccharomyces
fermentati, Saccharomyces lugwigii, Saccharomyces microellipsoides,
Saccharomyces pastorianus, Saccharomyces rosei, Candida albicans,
Candida cloaceae, Candida tropicalis, Candida utilis, Geotrichum
candidum, Hansenula americana, Hansenula anomala, Hansenula wingei,
and Aspergillus oryzae.
[0221] Probiotics and prebiotics may also include bacteria cell
wall derived agents such as peptidoglycan and other components
derived from gram-positive bacteria with a high content of
peptidoglycan. Exemplary gram-positive bacteria include
Lactobacillus acidophilus, Bifedobact thermophilum, Bifedobat
longhum, Streptococcus faecium, Bacillus pumilus, Bacillus
subtilis, Bacillus licheniformis, Lactobacillus acidophilus,
Lactobacillus casei, Enterococcus faecium, Bifidobacterium
bifidium, Propionibacterium acidipropionici, Propionibacteriium
freudenreichii, and Bifidobacterium pscudolongum.
[0222] Suitable herbals and herbal derivatives, as used herein,
refer to herbal extracts, and substances derived from plants and
plant parts, such as leaves, flowers and roots, without limitation.
Non-limiting exemplary herbals and herbal derivatives include
agrimony, alfalfa, aloe vera, amaranth, angelica, anise, barberry,
basil, bayberry, bee pollen, birch, bistort, blackberry, black
cohosh, black walnut, blessed thistle, blue cohosh, blue vervain,
boneset, borage, buchu, buckthorn, bugleweed, burdock, capsicum,
cayenne, caraway, cascara sagrada, catnip, celery, centaury,
chamomile, chaparral, chickweed, chicory, chinchona, cloves,
coltsfoot, comfrey, cornsilk, couch grass, cramp bark, culver's
root, cyani, cornflower, damiana, dandelion, devils claw, dong
quai, echinacea, elecampane, ephedra, eucalyptus, evening primrose,
eyebright, false unicorn, fennel, fenugreek, figwort, flaxseed,
garlic, gentian, ginger, ginseng, golden seal, gotu kola, gum weed,
hawthorn, hops, horehound, horseradish, horsetail, hoshouwu,
hydrangea, hyssop, iceland moss, irish moss, jojoba, juniper, kelp,
lady's slipper, lemon grass, licorice, lobelia, mandrake, marigold,
marjoram, marshmallow, mistletoe, mullein, mustard, myrrh, nettle,
oatstraw, oregon grape, papaya, parsley, passion flower, peach,
pennyroyal, peppermint, periwinkle, plantain, pleurisy root,
pokeweed, prickly ash, psyllium, quassia, queen of the meadow, red
clover, red raspberry, redmond clay, rhubarb, rose hips, rosemary,
rue, safflower, saffron, sage, St. John's wort, sarsaparilla,
sassafras, saw palmetto, scullcap, senega, senna, shepherd's purse,
slippery elm, spearmint, spikenard, squawvine, stillingia,
strawberry, taheebo, thyme, uva ursi, valerian, violet, watercress,
white oak bark, white pine bark, wild cherry, wild lettuce, wild
yam, willow, wintergreen, witch hazel, wood betony, wormwood,
yarrow, yellow dock, yerba santa, yucca and combinations
thereof.
[0223] Suitable non-limiting pigments include actinioerythrin,
alizarin, alloxanthin, .beta.-apo-2'-carotenal, apo-2-lycopenal,
apo-6'-lycopenal, astacein, astaxanthin, azafrinaldehyde,
aacterioruberin, aixin, .alpha.-carotine, .beta.-carotine,
.gamma.-carotine, .beta.-carotenone, canthaxanthin, capsanthin,
capsorubin, citranaxanthin, citroxanthin, crocetin,
crocetinsemialdehyde, crocin, crustaxanthin, cryptocapsin,
.alpha.-cryptoxanthin, .beta.-cryptoxanthin, cryptomonaxanthin,
cynthiaxanthin, decaprenoxanthin, dehydroadonirubin,
diadinoxanthin, 1,4-diamino-2,3-dihydroanthraquinone,
1,4-dihydroxyanthraquinone, 2,2'-Diketospirilloxanthin,
eschscholtzxanthin, eschscholtzxanthone, flexixanthin, foliachrome,
fucoxanthin, gazaniaxanthin, hexahydrolycopene, hopkinsiaxanthin,
hydroxyspheriodenone, isofucoxanthin, loroxanthin, lutein,
luteoxanthin, lycopene, lycopersene, lycoxanthin, morindone,
mutatoxanthin, neochrome, neoxanthin, nonaprenoxanthin,
OH-Chlorobactene, okenone, oscillaxanthin, paracentrone,
pectenolone, pectenoxanthin, peridinin, phleixanthophyll,
phoeniconone, phoenicopterone, phoenicoxanthin, physalien,
phytofluene, pyrrhoxanthininol, quinones, rhodopin, rhodopinal,
rhodopinol, rhodovibrin, rhodoxanthin, rubixanthone, saproxanthin,
semi-.alpha.-carotenone, semi-.beta.-carotenone, sintaxanthin,
siphonaxanthin, siphonein, spheroidene, tangeraxanthin,
torularhodin, torularhodin methyl ester, torularhodinaldehyde,
torulene, 1,2,4-trihydroxyanthraquinone, triphasiaxanthin,
trollichrome, vaucheriaxanthin, violaxanthin, wamingone, xanthin,
zeaxanthin, .alpha.-zeacarotene and combinations thereof.
[0224] Suitable non-limiting pharmaceutically acceptable agents
include an acid/alkaline-labile drug, a pH dependent drug, or a
drug that is a weak acid or a weak base. Examples of acid-labile
drugs include statins (e.g., pravastatin, fluvastatin and
atorvastatin), antiobiotics (e.g., penicillin G, ampicillin,
streptomycin, erythromycin, clarithromycin and azithromycin),
nucleoside analogs [e.g., dideoxyinosine (ddl or didanosine),
dideoxyadenosine (ddA), dideoxycytosine (ddC)], salicylates (e.g.,
aspirin), digoxin, bupropion, pancreatin, midazolam, and methadone.
Drugs that are only soluble at acid pH include nifedipine,
emonapride, nicardipine, amosulalol, noscapine, propafenone,
quinine, dipyridamole, josamycin, dilevalol, labetalol, enisoprost,
and metronidazole. Drugs that are weak acids include phenobarbital,
phenytoin, zidovudine (AZT), salicylates (e.g., aspirin), propionic
acid compounds (e.g., ibuprofen), indole derivatives (e.g.,
indomethacin), fenamate compounds (e.g., meclofenamic acid),
pyrrolealkanoic acid compounds (e.g., tolmetin), cephalosporins
(e.g., cephalothin, cephalaxin, cefazolin, cephradine, cephapirin,
cefamandole, and cefoxitin), 6-fluoroquinolones, and
prostaglandins. Drugs that are weak bases include adrenergic agents
(e.g., ephedrine, desoxyephedrine, phenylephrine, epinephrine,
salbutamol, and terbutaline), cholinergic agents (e.g.,
physostigmine and neostigmine), antispasmodic agents (e.g.,
atropine, methantheline, and papaverine), curariform agents (e.g.,
chlorisondamine), tranquilizers and muscle relaxants (e.g.,
fluphenazine, thioridazine, trifluoperazine, chlorpromazine, and
triflupromazine), antidepressants (e.g., amitriptyline and
nortriptyline), antihistamines (e.g., diphenhydramine,
chlorpheniramine, dimenhydrinate, tripelennamine, perphenazine,
chlorprophenazine, and chlorprophenpyridamine), cardioactive agents
(e.g., verapamil, diltiazem, gallapomil, cinnarizine, propranolol,
metoprolol and nadolol), antimalarials (e.g., chloroquine),
analgesics (e.g., propoxyphene and meperidine), antifungal agents
(e.g., ketoconazole and itraconazole), antimicrobial agents (e.g.,
cefpodoxime, proxetil, and enoxacin), caffeine, theophylline, and
morphine. In another embodiment, the drug may be a biphosphonate or
another drug used to treat osteoporosis. Non-limiting examples of a
biphosphonate include alendronate, ibandronate, risedronate,
zoledronate, pamidronate, neridronate, olpadronate, etidronate,
clodronate, and tiludronate. Other suitable drugs include estrogen,
selective estrogen receptor modulators (SERMs), and parathyroid
hormone (PTH) drugs. In yet another embodiment, the drug may be an
antibacterial agent. Suitable antibiotics include aminoglycosides
(e.g., amikacin, gentamicin, kanamycin, neomycin, netilmicin,
streptomycin, and tobramycin), carbecephems (e.g., loracarbef) a
carbapenem (e.g., certapenem, imipenem, and meropenem),
cephalosporins (e.g., cefadroxil cefazolin, cephalexin, cefaclor,
cefamandole, cephalexin, cefoxitin, cefprozil, cefuroxime,
cefixime, cefdinir, cefditoren, cefoperazone, cefotaxime,
cefpodoxime, ceftazidime, ceftibuten, ceftizoxime, and
ceftriaxone), macrolides (e.g., azithromycin, clarithromycin,
dirithromycin, erythromycin, and troleandomycin), monobactam,
penicillins (e.g., amoxicillin, ampicillin, carbenicillin,
cloxacillin, dicloxacillin, nafcillin, oxacillin, penicillin G,
penicillin V, piperacillin, and ticarcillin), polypeptides (e.g.,
bacitracin, colistin, and polymyxin B), quinolones (e.g.,
ciprofloxacin, enoxacin, gatifloxacin, levofloxacin, lomefloxacin,
moxifloxacin, norfloxacin, ofloxacin, and trovafloxacin),
sulfonamides (e.g., mafenide, sulfacetamide, sulfamethizole,
sulfasalazine, sulfisoxazole, and trimethoprim-sulfamethoxazole),
and tetracyclines (e.g., demeclocycline, doxycycline, minocycline,
and oxytetracycline). In an alternate embodiment, the drug may be
an antiviral protease inhibitor (e.g., amprenavir, fosamprenavir,
indinavir, lopinavir/ritonavir, ritonavir, saquinavir, and
nelfinavir). In a still another embodiment, the drug may be a
cardiovascular drug. Examples of suitable cardiovascular agents
include cardiotonic agents (e.g., digitalis (digoxin),
ubidecarenone, and dopamine), vasodilating agents (e.g.,
nitroglycerin, captopril, dihydralazine, diltiazem, and isosorbide
dinitrate), antihypertensive agents (e.g., alpha-methyldopa,
chlortalidone, reserpine, syrosingopine, rescinnamine, prazosin,
phentolamine, felodipine, propanolol, pindolol, labetalol,
clonidine, captopril, enalapril, and lisonopril), beta blockers
(e.g., levobunolol, pindolol, timolol maleate, bisoprolol,
carvedilol, and butoxamine), alpha blockers (e.g., doxazosin,
prazosin, phenoxybenzamine, phentolamine, tamsulosin, alfuzosin,
and terazosin), calcium channel blockers (e.g., amlodipine,
felodipine, nicardipine, nifedipine, nimodipine, nisoldipine,
nitrendipine, lacidipine, lercanidipine, verapamil, gallopamil, and
diltiazem), and anticlot agents (e.g., dipyrimadole).
[0225] A variety of commonly used excipients in pharmaceutical and
nutritive formulations may be utilized with any such agents
described above. Non-limiting examples of suitable excipients
include an agent selected from the group consisting of
non-effervescent disintegrants, a coloring agent, a
flavor-modifying agent, an oral dispersing agent, a stabilizer, a
preservative, a diluent, a compaction agent, a lubricant, a filler,
a binder, taste masking agents, an effervescent disintegration
agent, and combinations of any of these agents.
(V) Polymers
[0226] Another aspect of the present invention encompasses polymers
comprising a repeat unit having Formula (XX):
##STR00102##
[0227] wherein, [0228] R.sup.1, R.sup.2, R.sup.3, R.sup.4, and
R.sup.5 are independently chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0229] R.sup.6 is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0230] R.sup.7 is
optionally present, when present it is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0231] Z is chosen from
nitrogen, sulfur, sulfone, sulfoxide, and selenium; and [0232] n is
an integer .gtoreq.1.
[0233] The repeat unit of the polymers disclosed herein, therefore,
derives from the cyclic dimer compounds of Formulas (II) or (V). In
various embodiments, R.sup.2, R.sup.4, R.sup.5, R.sup.6, R.sup.7,
Z, and n may vary as detailed above in section (I). For example,
R.sup.2, R.sup.4, R.sup.5, R.sup.6, and R.sup.7, when present, may
be independently chosen from hydrogen, alkyl, aryl, alkylaryl,
substituted alkyl, substituted aryl, and substituted alkylaryl.
[0234] In some embodiments, R.sup.1 comprises
(CR.sup.8R.sup.9).sub.mYR.sup.10R.sup.11 and the repeat unit of the
polymer comprises Formula (XXa):
##STR00103##
[0235] wherein: [0236] R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6,
R.sup.8, R.sup.9, and R.sup.10 are independently chosen from
hydrogen, hydrocarbyl, and substituted hydrocarbyl; [0237] R.sup.7
and R.sup.11 are optionally present, when present they are
independently chosen from hydrogen, hydrocarbyl, and substituted
hydrocarbyl; [0238] Y and Z are independently chosen from nitrogen,
sulfur, sulfone, sulfoxide, and selenium; and [0239] n and m are
integers .gtoreq.1.
[0240] Each of R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6,
R.sup.7, R.sup.8, R.sup.9, R.sup.10, R.sup.11, Y, Z, n and m may
vary as described above in section (I). In various embodiments,
R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.8 and R.sup.9 are
hydrogen, n and m independently range from 1 to 10; Z and Y are
independently chosen from sulfur, sulfone, sulfoxide, and selenium.
In some iterations, R.sup.6 and R.sup.10 are lower chain alkyl, and
R.sup.7 and R.sup.11, if present, are independently hydrogen or
lower chain alkyl. In an exemplary embodiment, each of R.sup.2,
R.sup.3, R.sup.4, R.sup.5, R.sup.8 and R.sup.9 are hydrogen, both n
and m are 2, both Z and Y are sulfur, both R.sup.6 and R.sup.10 are
methyl, and neither R.sup.7 nor R.sup.11 are present.
[0241] In exemplary embodiments, the repeat unit comprises Formula
(XXV):
##STR00104##
[0242] wherein: [0243] p is an integer greater than 1; [0244]
provided that when p is less than 4, then the polymer has a
polydispersity index of less than about 1.3.
[0245] The polymers comprising repeat units having Formulas (XX),
(XXa), and (XXV) may have a variety of average molecular weights.
In various embodiments, the polymer may be an average molecular
weight that ranges from about 200 to about 2,000 Da, from about
2,000 to about 5,000 Da, from about 5,000 to about 10,000 Da, from
about 10,000 to about 30,000, from about 30,000 to about 60,000 Da,
from about 60,000 to about 100,000 Da, from about 100,000 to about
150,000 Da, from about 150,000 to about 300,000 Da, from about
300,000 to about 600,000 Da, from about 600,000 to about 1,000,000
Da, from about 1 million to about 2 million Da, from about 2
million to about 5 million Da, or greater than about 5 million
Da.
[0246] The polymers disclosed herein generally have a narrow molar
mass distribution. The polydispersity index (PDI), which is equal
to Mw/Mn, is generally less than about 1.8. In some embodiments,
the PDI is less than about 1.7, less than about 1.6, less than
about 1.5, less than about 1.4, less than about 1.3, less than
about 1.2, or less than about 1.1. In exemplary embodiments, the
polymers have a PDI of less than about 1.3.
[0247] The polymers disclosed herein contain essentially no monomer
or fraction of a monomer. The monomer may be a compound comprising
Formula (II) or (V), which are detailed above in section (I). In
certain embodiments, the monomer content of the homopolymer may be
less than about 5%, less than about 4%, less than about 3%, less
than about 2%, less than about 1% of a monomer, or less than about
0.5%.
[0248] The polymers disclosed herein may be linear, ring, branched
polymers or copolymers (see below). Branched polymers include be,
without limit, star polymers, comb polymers, brush polymers,
dendrimers, dendronized polymers, and ladder polymers. Polymers
prepared from optically pure monomers may be crystalline or
semi-crystalline.
[0249] The polymers comprising repeat units having Formulas (XX),
(XXa), or (XXV) may have one set of properties under one set of
conditions and a different set of properties under different
conditions. In some embodiments, the homopolymers provided herein
may be stable in aqueous solutions under approximately neutral pH.
In other embodiments, the homopolymers provided herein may
hydrolyze in aqueous solutions at pH values of less than about 6.0,
less than about 5.0, less than about 3.0, less than about 2.0, or
less than about 1.0.
[0250] In general, the repeat unit of the polymers disclosed herein
has at least one chiral center. In particular, the alpha carbon
adjacent to the carbonyl unit may be chiral. Depending upon the
identities of R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7,
R.sup.8, R.sup.9, R.sup.10, R.sup.11, Y, and Z, the repeat unit may
have additional chiral centers. Each chiral center may have an R or
an S configuration. In embodiments in which the repeat unit
comprises Formula (XXVI), each repeat unit has two chiral carbons.
Thus each repeat unit may have an RR, RS, SR, or SS
configuration.
(a) Homopolymers
[0251] In some embodiments, the polymer detailed above may be a
homopolymer. That is, each repeat unit is identical throughout the
length of the polymer.
[0252] In some embodiments, the homopolymer comprises Formula
(XXI):
##STR00105##
[0253] wherein: [0254] R is chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0255] R.sup.1, R.sup.2, R.sup.3, R.sup.4,
and R.sup.5 are independently chosen from hydrogen, hydrocarbyl,
and substituted hydrocarbyl; [0256] R.sup.6 is chosen from
hydrogen, hydrocarbyl, and substituted hydrocarbyl; [0257] R.sup.7
is optionally present, when present it is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0258] Z is chosen from
nitrogen, sulfur, sulfone, sulfoxide, and selenium; [0259] X is
chosen from oxygen and nitrogen; [0260] n is an integer .gtoreq.1;
and [0261] p is an integer greater than 1.
[0262] In various embodiments R may be hydrogen, alkyl, aryl,
alkylaryl, substituted alkyl, substituted aryl, and substituted
alkylaryl. In some embodiments, R is may be alkyl. In other
embodiments, R may be polyethylene oxide, polypropylene oxide,
polyvinyl alcohol, or another polymer. R.sup.1, R.sup.2, R.sup.3,
R.sup.4, R.sup.5, R.sup.6, R.sup.7, Z, and n may vary as described
above in section (I).
[0263] In one embodiment, R.sup.1 comprises
(CR.sup.8R.sup.9).sub.mYR.sup.10R.sup.11 and the polymer comprises
repeat units comprising Formula (XXa), as detailed above.
[0264] In one exemplary embodiment, the polymer comprises Formula
(XXV):
##STR00106##
[0265] wherein: [0266] R is chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0267] X is chosen from oxygen and
nitrogen; and [0268] p is an integer greater than 1; [0269]
provided that when p is less than 4, then the polymer has a
polydispersity index of less than about 1.3.
[0270] In some embodiments of the polymer comprising Formula
(XXVI), X is oxygen and R is C.sub.1 to C.sub.20 alkyl. In other
embodiments of the polymer comprising Formula (XXVI), XR may be an
amine.
(b) Copolymers
[0271] In some embodiments, the polymer detailed above may further
comprise at least one second repeat. That is, the polymer is a
copolymer comprising a first repeat unit comprising Formula (XX)
and at least one second repeat unit.
[0272] In some iterations of this embodiment, the second repeat
unit also comprises Formula (XX), however, the second repeat unit
is substituted differently in at least one position than the first
repeat unit comprising Formula (XX).
[0273] In other iterations, the second repeat unit may be an
acrylate, an aminoacrylate, an alkylene succinate, an alkylene
oxalate, an amide, an amino acid, an anhydride, an arylate, a
carbonate, a cellulose, a caprolactone, a cyanoacrylate, a cyclic
ether, a dihydropyran, a dioxane, a dioxanone, an ether ether
ketone, an ethylene glycol, a fumarate, an hydroxyl alkanoate, an
hydroxy ester, an imide, a ketal, a lactide, lactone, a
methacrylate, a methyl olefin, an orthoester, a phosphazine, a
styrene, a terephthalate, a tetrahydrofuran a trimethylene
carbonate, an urethane, a vinyl acetate, a vinyl ketone, a vinyl
halide, a derivative of any of the forgoing, or mixtures thereof.
In certain embodiments, the second repeat unit a lactide, a
lactone, a lactam, an hydroxyl alkanoate, a hydroxyl ester, a
cyclic ether, a tetrahydrofuran, a dioxane, a dioxanone, and
mixtures thereof. In exemplary embodiments, the second repeat unit
may be chosen from lactide and ethylene oxide. In one exemplary
embodiment, the first repeat unit comprises Formula (XXVI) and the
second repeat unit is lactide. In another exemplary embodiment, the
first repeat unit comprises Formula (XXV) and the second repeat
unit is ethylene oxide.
[0274] The weight ratio of the first repeat unit to the second
repeat unit may vary depending on the desired properties of the
copolymer. In some aspects, the weight ratio of the first repeat
unit comprising Formula (XX) to the second repeat unit may range
from about 99.9:0.1 to about 0.1:99.9. In various embodiments the
weight ratio of the first repeat unit comprising Formula (XX) to
the second repeat unit may be about 99:1, 95:5, 90:10, 85:15,
80:20, 75:25, 70:30, 65:35, 60:40, 55:45, 50:50, 45:55, 40:60,
35:65, 30:70, 25:75, 20:80, 15:85, 10:90, 5:95, or 1:99 weight %.
Similarly, in embodiments in which the combination comprises three
or more repeat units, the amount of each compound can and will
vary.
[0275] In various embodiments, the copolymer may be an average
molecular weight that ranges from about 200 to about 2,000 Da, from
about 2,000 to about 5,000 Da, from about 5,000 to about 10,000 Da,
from about 10,000 to about 30,000, from about 30,000 to about
60,000 Da, from about 60,000 to about 100,000 Da, from about
100,000 to about 150,000 Da, from about 150,000 to about 300,000
Da, from about 300,000 to about 600,000 Da, from about 600,000 to
about 1,000,000 Da, from about 1 million to about 2 million Da,
from about 2 million to about 5 million Da, or greater than about 5
million Da.
[0276] The copolymers disclosed herein may be may be alternating
copolymers, random copolymers, block copolymers, linear copolymers,
graft copolymers, or branched copolymers. Suitable branched
copolymers include star polymers, AB.sub.2 star polymers, palm-tree
AB.sub.n polymers, H-shaped B.sub.2AB.sub.2 polymers, dumbbell
polymers, star block AB.sub.n polymers, star A.sub.nB.sub.n
polymers, comb polymers, brush polymers, dendrimers, dendronized
polymers, ladder polymers, and so forth. The copolymers may be
crystalline or semi-crystalline.
(VI) Polymerization Processes
[0277] A further aspect of the present disclosure provides
processes for the formation of the polymers detailed above in
section (V).
[0278] The polymers detailed in section (V) may be prepared by
contacting a plurality of compounds comprising Formula (II) in the
presence of a catalyst to form the homopolymer comprising the
repeat unit comprising Formula (XX). The compound comprising
Formula (II) and the repeat unit comprising Formula (XX) have the
following structures:
##STR00107##
[0279] wherein: [0280] R.sup.1, R.sup.2, R.sup.3, R.sup.4, and
R.sup.5 are independently chosen from hydrogen, hydrocarbyl, and
substituted hydrocarbyl; [0281] R.sup.6 is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0282] R.sup.7 is
optionally present, when present it is chosen from hydrogen,
hydrocarbyl, and substituted hydrocarbyl; [0283] Z is chosen from
nitrogen, sulfur, sulfone, sulfoxide, and selenium; and [0284] n is
an integer .gtoreq.1.
[0285] Each of R.sup.1, R.sup.2, R.sup.4, R.sup.5, R.sup.6,
R.sup.7, Z, and n may be chosen as described above in section (I).
In some embodiments, R.sup.1 comprises
(CR.sup.8R.sup.9).sub.mYR.sup.10R.sup.11, wherein R.sup.8, R.sup.9,
R.sup.10, R.sup.11, Y, and m may be chosen as described in section
(I).
[0286] In an exemplary embodiment, the reacting compounds comprise
Formula (V) and the repeat unit of the polymers comprises Formula
(XXVI):
##STR00108##
[0287] The process comprises contacting a plurality of compounds
comprising Formula (II) or Formula (V) under the appropriate ring
opening conditions to facilitate polymerization. In general, the
polymerization reaction is conducted in the presence of a catalyst.
Suitable catalysts include, without limit, tin(II) octanoate
(stannous octanoate), aluminum(III) isopropoxide, zinc(II) lactate,
yttrium complexes, bis- and trisaryl tin complexes,
heterobimetallic iron(II) complexes, titanium complexes with
bridged-biphenolate ligands, cationic aluminum complexes, pyridine
catalysts, and the like. In an exemplary embodiment, the catalyst
may be stannous octanoate.
[0288] The amount of catalyst used in the reaction can and will
vary. In general, the amount of catalyst may range from about 0.001
wt % of the amount of the compound comprising Formula (II) or
Formula (V) to about 2 wt % of the compound comprising Formula (II)
or Formula (V). In some embodiments, the catalyst may be added in
an amount below 2 wt %, below 1 wt %, or below 0.1 wt %. More
preferably, the catalyst may be provided in the reaction in a
weight percentage of about 0.01, 0.02, 0.03, 0.04, 0.05, 0.06,
0.07, 0.08, 0.09, or 0.10 mol % to the compound comprising Formula
(IIb).
[0289] The reaction may be conducted in the presence of a solvent.
Alternatively the reaction may be conducted neat. In embodiments in
which a solvent is included in the reaction mixture, the choice of
solvent will depend upon the identity of the compounds comprising
Formula (II) or Formula (V). Examples of suitable solvents are
detailed above in section (IIa). In an exemplary embodiment, the
solvent may be toluene. The amount of solvent added to the reaction
mixture can and will vary. Typically, the weight-to-weight ratio of
the solvent to the compound comprising Formula (II) or Formula (V)
may range from about 1:1 to about 100:1. In various embodiments,
the weight-to-weight ratio of the solvent to the compound
comprising Formula (II) or Formula (V) may range from about 1:1 to
5:1, from about 5:1 to about 20:1, from about 20:1 to about 40:1,
from about 40:1 to about 80:1, or from about 80:1 to about
100:1.
[0290] The reaction mixture may further comprise a ring opening
initiator. The initiator may be any compound (i.e., a small
molecule or a polymer) comprising at least one hydroxyl group
and/or an amine group. Suitable initiators include water, alcohols,
polyols (e.g., glycerol, sugar alcohols, etc,) polymers comprising
hydroxyl groups (e.g., polyethylene oxide, polypropylene oxide,
polyvinyl alcohol), glycols, polyglycols, and primary or secondary
amines of low molecular weight. In exemplary embodiments the
initiator may be water, methanol, ethanol, propanol, butanol,
pentanol, hexanol, heptanol, octanol, nonanol, decanol,
polyethylene oxide, polyvinyl alcohol, and the like.
[0291] The temperature of the polymerization reaction may vary. In
general, the reaction is conducted at a temperature that ranges
from about 100.degree. C. to about 200.degree. C. In various
embodiments, the temperature of the reaction may range from about
100.degree. C. to about 120.degree. C., from about 120.degree. C.
to about 140.degree. C., from about 140.degree. C. to about
160.degree. C., from about 160.degree. C. to about 200.degree. C.
In exemplary embodiments, the temperature of the reaction may be
about 140.degree. C., about 160.degree. C., or any temperature
in-between. In general, the reaction is conducted under an inert
atmosphere. For example, the reaction may be performed under
nitrogen, under argon, or another inert gas.
[0292] The duration of the reaction can and will vary. In general,
the duration of the reaction may range from about 1 hour to about 3
days. In various embodiment, the duration of the reaction may range
from about 1 to 5 hours, from about 5 to 10 hours, from about 10 to
18 hours, from about 18 to 24 hours, from about 24 to about 30
hours, from about 30 to about 40 hours, or from about 40 hours to
about 60 hours.
[0293] In some embodiments, the polymer may be prepared by an
extrusion process. Generally, processes of extrusion involve
feeding the reaction mixture into an extruder which heats and
shears the mixture. Generally, shearing occurs through an apparatus
which pushes the heated polymer through an orifice. The extruder
may be chosen from any commercially available extruder and may be a
single screw extruder or preferably a twin-screw extruder that
mechanically shears the mixture with the screw elements.
[0294] In general, substantially all of the compounds comprising
Formula (II) or Formula (V) are polymerized and converted into the
polymer. In various embodiments, the conversion of the compounds
comprising Formula (II) or Formula (V) may be greater than about
90%, greater than about 95%, greater than about 98%, or greater
than about 99%. In general, the polymer is substantially free of
monomer (i.e., the compound comprising Formula (IIb) or Formula
(V)).
[0295] The resultant polymer may be isolated and/or purified from
the reaction mixture using means well known in the art including
size exclusion chromatography, HPLC, ion-exchange chromatography,
other types of chromatography, precipitation, and/or
crystallization.
[0296] The copolymers detailed in section (V)(b) may be prepared by
contacting a plurality of compounds comprising Formula (II) or
Formula (V) with a plurality of at least one additional type of
monomer during the polymerization process. The additional monomers
may be added concurrently with the compounds comprising Formula
(II) or Formula (V), may be added after the compounds comprising
Formula (II) or Formula (V), or may be added alternately with the
compounds comprising Formula (II) or Formula (V). Those skilled in
the art will appreciate that many variations are possible,
considering the many different types of copolymers that can be
made.
[0297] The additional monomers may be chosen from acrylates,
aminoacrylates, alkylene succinates, alkylene oxalates, amides,
amino acids, anhydrides, arylates, carbonates, cellulose,
caprolactone, caprolactam, cyanoacrylates, cyclic ethers,
dihydropyrans, dioxanes, dioxanones, ether ether ketones, ethylene
glycol, fumarates, hydroxy alkanoates, hydroxy esters, imides,
ketals, lactides, lactones, methacrylates, methyl olefins,
orthoesters, phosphazines, styrenes, terephthalates, tetrafurans.
trimethylene carbonate, urethanes, vinyl acetates, vinyl ketones,
vinyl halides, derivatives, isomers, and mixtures thereof.
[0298] The ratio of the additional monomer to the compounds
comprising Formula (II) or Formula (V) may range from about
99.9:0.1 to about 0.1:99.9 weight %. For example, additional
monomers may be provided in a ratio of 99:1, 95:5, 90:10, 85:15,
80:20, 75:25, 70:30, 65:35, 60:40, 55:45, 50:50, 45:55, 40:60,
35:65, 30:70, 25:75, 20:80, 15:85, 10:90, 5:95, or 1:99 weight % to
the compounds comprising Formula (II) or Formula (V). Similarly, in
embodiments in which the combination comprises three or more
monomers, the amount of each monomer can and will vary.
(VII) Applications
[0299] The polymers detailed above in section (V) may be used in a
variety of applications. Non-limiting examples of suitable uses
include plasticizers, processing aids, adhesives, coatings,
lacquers, films, emulsifiers, antioxidant agents, antimicrobial
agents, anticorrosive agents, nutritive agents, or feed additives.
In various embodiments, the polymers disclosed herein may be used
in packaging materials (e.g., trash bags, biodegradable bags,
grocery bags, wrappings, food containers, film wrapping, laminated
papers, bottles), consumer goods (e.g., fast-food tableware,
containers, egg cartons, razor handles, toothbrushes, pens,
cartridges, toys), disposable non-wovens (e.g., engineered fabrics;
diaper backings, surgical gowns, drapes, and the like), cosmetics,
personal care products, home care products, medical applications
(e.g., drug delivery, scaffolds for tissue engineering, medical
prostheses, wound dressing, sutures, bone replacement, fixation of
fractures, fixation of ligaments, cartilage repair, menisci repair,
medical devices, stents, orthopedic/surgical materials (e.g.,
screws, pins, plugs, etc.), haemostatic devices, sensor devices),
and agricultural applications (e.g., mulch films, planters).
(VIII) Polymer Compositions
[0300] In yet another aspect, the present disclosure encompasses
polymer compositions. In some embodiments, the polymer composition
comprises a first polymer as described in section (V) and at least
one additional polymer to form a polymer blend. As used herein, a
blend is a macroscopic homogeneous or miscible mixture of two or
more different polymers and is formed by tailoring compositions to
meet specific end-use requirements.
[0301] In various embodiments, the additional polymer may be
selected from crystalline and semicrystalline polymers. Examples of
suitable polymers, without limitation, are polymers of acrylates,
aminoacrylates, alkylene succinates, alkylene oxalates, amides,
amino acids, anhydrides, arylates, carbonates, cellulose,
caprolactone, cyanoacrylates, cyclic ethers, dihydropyrans,
dioxanes, dioxanones, ether ether ketones, ethylene glycol,
fumarates, hydroxy alkanoates, hydroxy esters, imides, ketals,
lactides, lactones, methacrylates, methyl olefins, orthoesters,
phosphazines, styrenes, terephthalates, tetrafurans. trimethylene
carbonate, urethanes, vinyl acetates, vinyl ketones, vinyl halides,
derivatives, isomers, and mixtures thereof. In exemplary
embodiments, the second polymer may be chosen from poly(lactide),
poly(ethyl cellulose), and polyvinyl alcohol.
[0302] The additional polymer may vary in molecular weight. In some
embodiments, the additional polymer may range from about 500 Da to
greater than 1,000,000 Da. In some embodiments, the molecular
weight of the additional polymer may be about 2,000 Da, 10,000 Da,
20,000 Da, 30,000 Da, 40,000 Da, 50,000 Da, 60,000 Da, 70,000 Da,
80,000 Da, 90,000 Da, 100,000 Da, 500,000 Da, 1,000,000 Da and may
range between and including any two of these values. The additional
polymer may be characterized by a weight-average molecular weight.
In some aspects, the weight-average molecular weight of the
additional polymer used in the blend may be at least 500 Da. In
other aspects, the weight-average molecular weight of the
additional polymers may be about 1,000 Da to about 1,000,000
Da.
[0303] The amount of the first polymer detailed in section (V) and
the additional polymer may depend on the desired properties of the
combination. In some aspects, the weight ratio of the first polymer
to the additional polymer may range from about 99.9:0.1 to about
0.1:99.9 weight %. In various embodiments the weight ratio of the
first polymer to the additional polymer may be about 99:1, 95:5,
90:10, 85:15, 80:20, 75:25, 70:30, 65:35, 60:40, 55:45, 50:50,
45:55, 40:60, 35:65, 30:70, 25:75, 20:80, 15:85, 10:90, 5:95, or
1:99 weight %. In some embodiments, the blend comprises more than
one additional polymer. In embodiments in which the combination
comprises two or more additional polymers, the amount of each
polymer can and will vary.
[0304] In other embodiments, the polymer composition may be a feed
composition comprising a polymer from section (V) and at least one
additional agent chosen from one or more of the following:
carbohydrates, fats, proteins, amino acids, and alpha hydroxy
acids. Suitable sources of carbohydrates fats, proteins, amino
acids, and alpha hydroxy acids are detailed above in section
(IV)(a). In still other embodiments, the polymer composition may
comprise a polymer from section (V) and at least one nutritive
and/or pharmaceutical agent. Suitable nutritive and pharmaceutical
agents are detailed above in section (IV)(b).
DEFINITIONS
[0305] When introducing elements of the embodiments described
herein, the articles "a", "an", "the" and "said" are intended to
mean that there are one or more of the elements. The terms
"comprising", "including" and "having" are intended to be inclusive
and mean that there may be additional elements other than the
listed elements.
[0306] The compounds described herein have asymmetric centers.
Compounds of the present invention containing an asymmetrically
substituted atom may be isolated in optically active or racemic
form. All chiral, diastereomeric, racemic forms and all geometric
isomeric forms of a structure are intended, unless the specific
stereochemistry or isomeric form is specifically indicated.
[0307] The term "acyl," as used herein alone or as part of another
group, denotes the moiety formed by removal of the hydroxyl group
from the group COOH of an organic carboxylic acid, e.g., RC(O)--,
wherein R is R.sup.1, R.sup.1O--, R.sup.1R.sup.2N--, or R.sup.1S--,
R.sup.1 is hydrocarbyl, heterosubstituted hydrocarbyl, or
heterocyclo, and R.sup.2 is hydrogen, hydrocarbyl, or substituted
hydrocarbyl.
[0308] The term "acyloxy," as used herein alone or as part of
another group, denotes an acyl group as described above bonded
through an oxygen linkage (O), e.g., RC(O)O-- wherein R is as
defined in connection with the term "acyl."
[0309] The term "allyl," as used herein not only refers to compound
containing the simple allyl group (CH.sub.2.dbd.CH--CH.sub.2--),
but also to compounds that contain substituted allyl groups or
allyl groups forming part of a ring system.
[0310] The term "alkyl" as used herein describes groups which are
preferably lower alkyl containing from one to eight carbon atoms in
the principal chain and up to 20 carbon atoms. They may be straight
or branched chain or cyclic and include methyl, ethyl, propyl,
isopropyl, butyl, hexyl and the like.
[0311] The term "alkenyl" as used herein describes groups which are
preferably lower alkenyl containing from two to eight carbon atoms
in the principal chain and up to 20 carbon atoms. They may be
straight or branched chain or cyclic and include ethenyl, propenyl,
isopropenyl, butenyl, isobutenyl, hexenyl, and the like.
[0312] The term "alkoxide" or "alkoxy" as used herein is the
conjugate base of an alcohol. The alcohol may be straight chain,
branched, cyclic, and includes aryloxy compounds.
[0313] The term "alkynyl" as used herein describes groups which are
preferably lower alkynyl containing from two to eight carbon atoms
in the principal chain and up to 20 carbon atoms. They may be
straight or branched chain and include ethynyl, propynyl, butynyl,
isobutynyl, hexynyl, and the like.
[0314] The term "aromatic" as used herein alone or as part of
another group denotes optionally substituted homo- or heterocyclic
conjugated planar ring or ring system comprising delocalized
electrons. These aromatic groups are preferably monocyclic (e.g.,
furan or benzene), bicyclic, or tricyclic groups containing from 5
to 14 atoms in the ring portion. The term "aromatic" encompasses
"aryl" groups defined below.
[0315] The terms "aryl" or "Ar" as used herein alone or as part of
another group denote optionally substituted homocyclic aromatic
groups, preferably monocyclic or bicyclic groups containing from 6
to 10 carbons in the ring portion, such as phenyl, biphenyl,
naphthyl, substituted phenyl, substituted biphenyl, or substituted
naphthyl.
[0316] The term "copolymer" refers to a polymer containing two or
more different repeat units.
[0317] The term "crystalline polymer" as used herein refers to a
polymer having the characteristic or regular three-dimensional
packing.
[0318] The term "enrichment" means an amount above the statistical
distribution if all chiral centers had an equal probability of
being alpha or beta.
[0319] The terms "carbocyclo" or "carbocyclic" as used herein alone
or as part of another group denote optionally substituted, aromatic
or non-aromatic, homocyclic ring or ring system in which all of the
atoms in the ring are carbon, with preferably 5 or 6 carbon atoms
in each ring. Exemplary substituents include one or more of the
following groups: hydrocarbyl, substituted hydrocarbyl, alkyl,
alkoxy, acyl, acyloxy, alkenyl, alkenoxy, aryl, aryloxy, amino,
amido, acetal, carbamyl, carbocyclo, cyano, ester, ether, halogen,
heterocyclo, hydroxyl, keto, ketal, phospho, nitro, and thio.
[0320] The terms "epoxy" or "epoxide" as used herein means a cyclic
ether. The ring structure generally comprises from 2 to 5 carbon
atoms in the ring.
[0321] The terms "halogen" or "halo" as used herein alone or as
part of another group refer to chlorine, bromine, fluorine, and
iodine.
[0322] The term "heteroatom" refers to atoms other than carbon and
hydrogen.
[0323] The term "heteroaromatic" as used herein alone or as part of
another group denotes optionally substituted aromatic groups having
at least one heteroatom in at least one ring, and preferably 5 or 6
atoms in each ring. The heteroaromatic group preferably has 1 or 2
oxygen atoms and/or 1 to 4 nitrogen atoms in the ring, and is
bonded to the remainder of the molecule through a carbon. Exemplary
groups include furyl, benzofuryl, oxazolyl, isoxazolyl,
oxadiazolyl, benzoxazolyl, benzoxadiazolyl, pyrrolyl, pyrazolyl,
imidazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidyl, pyrazinyl,
pyridazinyl, indolyl, isoindolyl, indolizinyl, benzimidazolyl,
indazolyl, benzotriazolyl, tetrazolopyridazinyl, carbazolyl,
purinyl, quinolinyl, isoquinolinyl, imidazopyridyl, and the like.
Exemplary substituents include one or more of the following groups:
hydrocarbyl, substituted hydrocarbyl, alkyl, alkoxy, acyl, acyloxy,
alkenyl, alkenoxy, aryl, aryloxy, amino, amido, acetal, carbamyl,
carbocyclo, cyano, ester, ether, halogen, heterocyclo, hydroxyl,
keto, ketal, phospho, nitro, and thio.
[0324] The terms "heterocyclo" or "heterocyclic" as used herein
alone or as part of another group denote optionally substituted,
fully saturated or unsaturated, monocyclic or bicyclic, aromatic or
non-aromatic groups having at least one heteroatom in at least one
ring, and preferably 5 or 6 atoms in each ring. The heterocyclo
group preferably has 1 or 2 oxygen atoms and/or 1 to 4 nitrogen
atoms in the ring, and is bonded to the remainder of the molecule
through a carbon or heteroatom. Exemplary heterocyclo groups
include heteroaromatics as described above. Exemplary substituents
include one or more of the following groups: hydrocarbyl,
substituted hydrocarbyl, alkyl, alkoxy, acyl, acyloxy, alkenyl,
alkenoxy, aryl, aryloxy, amino, amido, acetal, carbamyl,
carbocyclo, cyano, ester, ether, halogen, heterocyclo, hydroxyl,
keto, ketal, phospho, nitro, and thio.
[0325] The term "homopolymer" refers to a polymer containing a
single type of repeat unit.
[0326] The terms "hydrocarbon" and "hydrocarbyl" as used herein
describe organic compounds or radicals consisting exclusively of
the elements carbon and hydrogen. These moieties include alkyl,
alkenyl, alkynyl, and aryl moieties. These moieties also include
alkyl, alkenyl, alkynyl, and aryl moieties substituted with other
aliphatic or cyclic hydrocarbon groups, such as alkaryl, alkenaryl
and alkynaryl. Unless otherwise indicated, these moieties
preferably comprise 1 to 20 carbon atoms.
[0327] The term "protecting group" as used herein denotes a group
capable of protecting a particular moiety, wherein the protecting
group may be removed, subsequent to the reaction for which the
protection is employed, without disturbing the remainder of the
molecule. A variety of protecting groups and the synthesis thereof
may be found in "Protective Groups in Organic Synthesis" by T. W.
Greene and P. G. M. Wuts, John Wiley & Sons, 1999.
[0328] The term "semi-crystalline polymer" as used herein refers to
a polymer with both regions that are "crystalline" as describe
above, and regions that are amorphous, having no regular packing to
the three-dimensional structure.
[0329] The "substituted hydrocarbyl" moieties described herein are
hydrocarbyl moieties which are substituted with at least one atom
other than carbon, including moieties in which a carbon chain atom
is substituted with a heteroatom such as nitrogen, oxygen, silicon,
phosphorous, boron, or a halogen atom, and moieties in which the
carbon chain comprises additional substituents. These substituents
include alkyl, alkoxy, acyl, acyloxy, alkenyl, alkenoxy, aryl,
aryloxy, amino, amido, acetal, carbamyl, carbocyclo, cyano, ester,
ether, halogen, heterocyclo, hydroxyl, keto, ketal, phospho, nitro,
and thio.
[0330] Having described the invention in detail, it will be
apparent that modifications and variations are possible without
departing from the scope of the invention defined in the appended
claims.
EXAMPLES
[0331] The following examples illustrate various embodiments of the
invention.
Example 1: Preparation of
3,6-bis(2-Methylthio)ethyl-1,4-dioxane-2,5 Dione
[0332] The cyclic dimer 3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5
dione was prepared according to the following reaction scheme:
##STR00109##
[0333] A solution of 524.6 g of Alimet.RTM. (88%
2-hydroxy-4-(methylthio)butanoic acid (HMTBa) in toluene (14054 g)
was treated with catalytic p-toluene sulfonic acid monohydrate
(21.1 g). The reaction flask was fitted with a Dean Stark trap and
condenser. The reaction was heated to 110.degree. C. and
approximately 95 mL of water was collected over about 5 hours.
After 5 hours, the reaction was cooled to room temperature and
washed twice with saturated sodium bicarbonate, and twice with
water. The toluene was then removed under reduced pressure. The
residue was dried to a solid under high vacuum. To the solid
residue was then added 300 mL of methyl t-butyl ether, and the
solid dissolved at 50.degree. C. The solution was cooled to ambient
temperature, and then to 2-4.degree. C. to crystallize. The
solution was warmed to ambient temperature and the solid filtered
off and washed with minimal methyl t-butyl ether. The solid was
dried on high vacuum to give 91.4 g (22 mol) of an off-white solid.
LC/MS showed a racemic mixture (2 peaks) both with M+H=265,
M+Na=287. .sup.1H NMR (500 MHz, CHLOROFORM-d, racemic mixture) ppm
2.07-2.16 (m, 6H), 2.21-2.46 (m, 4H), 2.65-2.83 (m, 4H), 5.17-5.32
(m, 2H). TLC (25% ethyl acetate/heptanes) rf: 0.16.
Example 2. Distillation of 2-Hydroxy-4-(Methylthio)butanoic
Acid
[0334] In a flask 11 g of HMTBa and 11 mL of conc. HCl were added.
The mixture was heated to 90.degree. C. for 1 hour. The mixture was
cooled and then concentrated at 5-10 Torr for 1.25 hrs until the
pot temperature reached 100.degree. C. After cooling to room
temperature an aliquot of the reaction mixture was analyzed by
HPLC. The chromatogram shown in FIG. 1A reveals the presence of
monomers, dimers, trimers, and tetramers of HMTBa in the reaction
mixture. To confirm that no cyclic dimer was present in the
reaction mixture, an aliquot of the cyclic dimer prepared
essentially as described in Example 1 was subjected to HPLC (using
the same parameters as used for the analysis of the reaction
mixture). FIG. 1B presents an overlay of the cyclic dimer
chromatogram onto the HMTBa oligomer chromatogram. This analysis
revealed that the cyclic dimer had a different elution time than
the HMTBa oligomers.
Example 3. Azeotropic Distillation of
2-Hydroxy-4-(Methylthio)butanoic Acid
[0335] In a flask was added purified HMTBa and xylenes (no acid was
present). The mixture was heated and water was removed by azetropic
distillation for 4-6 hours. After cooling to room temperature an
aliquot of the reaction mixture was analyzed by HPLC. As shown in
FIG. 2A, the sample contained monomers, dimers, trimers, and
tetramers of HMTBa, but no cyclic dimer. To confirm this, an
aliquot of the cyclic dimer prepared essentially as described in
Example 1 was subjected to HPLC (using the same parameters as used
for the analysis of the reaction mixture). FIG. 2B presents an
overlay of the cyclic dimer chromatogram onto the HMTBa oligomer
chromatogram. This analysis revealed that the cyclic dimer had a
different elution time than the HMTBa oligomers.
Example 4. Separation of Diastereomers
[0336] Alimet.RTM. and p-toluene sulfonic acid were reacted as
described in Example 1. An aliquot (4.7 g) of the resulting solid
was subjected to chiral chromatography (Chiralpak IA column, eluted
with 70:30 hexane:THF at 25.degree. C., with UV detection at 220
nm) and yielded three samples of the different diastereomers. The
samples are detailed in Table 6.
TABLE-US-00006 TABLE 6 Diastereomer Samples Sample Diastereomer
Excess Retention time Recovery* #1 >99% 5.323 min 1.09 g (92.9%)
#2 99.3% 6.464 min 1.18 g (100%) #3 >99% 12.295 min 2.09 g
(89.3%) *% recovery does not take into account any residual BHT
left in the product
(-)-3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione
[0337] 315 mg of #1 was suspended in 10 mL of methyl t-butyl ether
and then filtered, and dried under high vacuum to give 235 mg of #1
with 98.7% purity (HPLC). .alpha..sub.D.sup.25 (c=1.042,
CH.sub.2Cl.sub.2): -250.212. LCMS MH+ 265, M+Na 287.
(+)-3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione
[0338] 309 mg of #2 was suspended in 10 mL of methyl t-butyl ether
and then filtered, and dried under high vacuum to give 190 mg of #2
with >99% purity (HPLC). .alpha..sub.D.sup.25 (c=1.037,
CH.sub.2Cl.sub.2): +250.263. LCMS MH+ 265, M+Na 287.
(meso)-3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione
[0339] 420 mg of #3 was suspended in 10 mL of methyl t-butyl ether
and then filtered, and dried under high vacuum to give 250 mg of #3
with 96% purity (HPLC). .alpha..sub.D.sup.25 (c=1.036,
CH.sub.2Cl.sub.2): =0.degree. (racemic). LCMS MH+ 265, M+Na
287.
Example 5. Polymerization of
3,6-bis(2-Methylthio)ethyl-1,4-dioxane-2,5 Dione
[0340] Into a 25 ml flask was placed 1.5 grams of
3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione as prepared in
Example 1 and a stirring bar, and then vacuum was applied on this
flask for 1.5 h. Then 0.15 ml of catalyst solution (stannous
octoate in toluene, 7.63 mM) was injected into the flask, which was
filled with nitrogen. The temperature of the mixture was controlled
at 140.degree. C. for 48 hours. Analysis of the polymer by gel
permeation chromatography (GPC) revealed that the number-average
molar mass (Mn) was 3470 g/mol.
(Mn=.SIGMA.n.sub.i/.SIGMA.n.sub.i/M.sub.i). The Polydispersity
Index (PDI) was 1.26. (PDI=Mw/Mn; Mw=mass-average molar
mass=.SIGMA.n.sub.iM.sub.i/.SIGMA.n.sub.i).
Example 6. Polymerization--Trial 2
[0341] Into a 25 ml flask was placed 1.5 grams of
3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione and a stirring
bar, and then a vacuum was applied on this flask for 1.5 h. Then
0.15 ml of catalyst solution (stannous octoate in toluene, 7.63 mM)
was injected into the flask, which was filled with nitrogen,
followed by addition of 2.5 mg of 1-octanol. The temperature of the
mixture was controlled at 140.degree. C. for 48 hours. Analysis of
the resultant polymer revealed that it had a Mn of 2620 g/mol and a
PDI of 1.5.
Example 7. Polymerization--Trial 3
[0342] Into a 25 ml flask was placed a magnetic stirring bar and
1.5 grams of 3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione which
was dried in vacuum oven at 30.degree. C. for 3 days. The monomer
was further dried on a vacuum line at room temperature. After the
flask was filled with dry N.sub.2, 0.15 ml of catalyst (stannous
octoate in toluene, 7.63 mM) was added. The temperature of the
polymerization was controlled at 160.degree. C. for 48 hours.
Analysis of the polymer revealed that the Mn was 4700 g/mol and the
PDI was 1.46.
Example 8. Polymerization--Trial 4
[0343] Into a 25 ml flask was placed a magnetic stirring bar and
1.5 grams of 3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione which
was dried in vacuum oven at 30.degree. C. for 3 days. The monomer
was further dried on a vacuum line at room temperature. After the
flask was filled with dry N.sub.2, 0.15 ml of catalyst (stannous
octoate in toluene, 7.63 mM) and 3.25 mg octanol was added. The
temperature of the polymerization was controlled at 160.degree. C.
for 48 hours. GPC analysis revealed that the polymer had a Mn of
3500 g/mol and a PDI of 1.69.
Example 9. Polymerization--Trial 5
[0344] Into a 25 ml flask was placed a magnetic stirring bar and
1.5 grams of 3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione which
was dried in vacuum oven at 50.degree. C. overnight. The monomer
was further dried on a vacuum line at room temperature for 1 hour.
After the flask was filled with dry N.sub.2, 4.5 mg of stannous
octoate was added. The temperature of the polymerization was ramped
to and controlled at 140.degree. C. for 28 hours. Analysis revealed
that the Mn of the polymer was 8600 g/mol and the PDI was 1.27. The
structure of the polymer was analyzed by .sup.1H-NMR. FIG. 3
presents the NMR spectrum.
Example 10. Polymerization--Trial 6
[0345] Into a 25 ml flask was placed a magnetic stirring bar and
1.5 grams of 3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione which
was dried by vacuum pumping at 50.degree. C. for several days. The
monomer was further dried on a vacuum line at room temperature for
1 hour. After the flask was filled with dry N.sub.2, 3 mg of
stannous octoate was added. The temperature of the polymerization
was ramped to and controlled at 140.degree. C. for 22 hours. GPC
analysis revealed that the Mn of the polymer was 3.3.times.10.sup.4
g/mol and the PDI was 1.22. GPC coupled with light scattering
detectors (GPC-LS) revealed that the Mn was 8.8.times.10.sup.4
g/mol and the PDI was of 1.34.
Example 11. Polymerization--Trial 7
[0346] Into a 25 ml shlenk reaction tube was placed a magnetic
stirring bar and 10.24 grams of
3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione which was
thoroughly dried by vacuum at 50.degree. C. for several days. The
monomer was further dried on a vacuum line at 58.degree. C. for 2
hour. After the reactor was filled with dry N.sub.2, 9 mg of
stannous octoate was added. The temperature of the polymerization
was ramped to and controlled at 140.degree. C. for 21 hours. GPC
analysis revealed an Mn of 6.3.times.10.sup.4 g/mol and a PDI was
1.52. GPC-LS analysis revealed that the Mn was 1.1.times.10.sup.5
g/mol and the PDI was 1.36.
Example 12. Polymerization--Trial 8
[0347] Into a 500 ml shlenk reaction flask was placed 120 grams of
dry 3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione, which was
further dried on a vacuum line for 2.5 hours at 60.degree. C. After
the flask was filled with dry N.sub.2, 0.1 ml of stannous octoate
and 19 ml of octanol were injected to initiate the ring opening
polymerization of the monomer. The mixture was heated up to and
thermostated at 140.degree. C. The reaction was continued for 2.5
hours. The polymer was recovered by pouring the reaction mixture
into a container under N.sub.2 protection. Conversion of the
monomer was 98%. GPC analysis revealed that the Mn of the polymer
was 1.3.times.10.sup.3 g/mol and the PDI was 1.2.
Example 13. Kinetic Study of Ring Opening Polymerization
[0348] Into a 500 ml shlenk reaction flask was placed 122 grams of
dry 3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione, which was
further dried on a vacuum line for 1 hour at 53-60.degree. C. After
the flask was filled with dry N.sub.2, 0.1 ml of stannous octoate
was injected to catalyze the ring opening polymerization of the
monomer. The mixture was heated up to and thermostated at
140.degree. C. The reaction was continued for 23.5 hours. At
certain interval of reaction time, aliquots were removed and the
molecular weight was analyzed by GPC. The GPC chromatograms from
the various time points are shown in FIG. 4. The final polymer was
recovered by pouring the reaction mixture into a container under
N.sub.2 protection. Conversion of the monomer was 96.1%. The Mn of
the polymer was 4.35.times.10.sup.4 g/mol and the PDI was 1.58.
Example 14. Depolymerization of Polymer Formed From
3,6-bis(2-Methylthio)ethyl-1,4-dioxane-2,5 Dione
[0349] First, the polymer was formed by charging 3.5 g of the
cyclic dimer (3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione)
into a shlenk reaction flask, followed by injection of 0.15 ml of
octanol and 5 droplets of stannous octoate (.about.15 mg). The
reaction mixture was heated up to 140.degree. C. and the reaction
was allowed to proceed for 24 hours. An aliquot of the mixture was
sampled and the conversion of the cyclic dimer to the polymer was
determined to be 95 wt % (the concentration of cyclic dimer in the
final mixture was 5%) (see FIG. 5).
[0350] For the thermal cracking step, the reactor was set up with
distillation apparatus. The temperature of the mixture was raised
to 200.degree. C. and vacuum (.about.500 mTorr) was applied. The
distillation was continued for 2 hours. An aliquot of the distilled
reaction mixture and the distillates were analyzed by HPLC (see
FIG. 6 and FIG. 7, respectively). Both HMTBa and the cyclic dimer
(3,6-bis(2-methylthio)ethyl-1,4-dioxane-2,5 dione) were detected in
the distillates. The mixture in the reaction pot was analyzed by
GPC and it was determined that the concentration of cyclic dimer
was 8.8%. The increase of the concentration of the cyclic dimer and
the presence of HMTBA in the distillate strongly suggests the
decomposition of the polymer into monomers during the thermal
cracking step.
Example 15. Depolymerization of Polymer
[0351] The polymer was formed by charging 3.0 g of cyclic dimer
into a shlenk reaction flask, followed by injection of 5 droplets
of stannous octoate (.about.15 mg). The reaction mixture was heated
to 140.degree. C. and reacted for 22 hours. An aliquot of the
mixture was sampled and the conversion of the cyclic dimer to the
polymer was determined to be 97%.
[0352] For the thermal cracking step, the reactor was set up with a
condenser and connected to a vacuum (200-500 mTorr). The
temperature of the mixture was raised to 200.degree. C. and kept
for 2.5 h. The final reaction mixture was analyzed by GPC, which
revealed that the concentration of the cyclic dimer in the mixture
was 7.0%.
Example 16. Depolymerization of Polymer Formed From HMTBa
[0353] To a flask was added 4.0 g of oligomers of HMTBa
(Mn=1.0.times.10.sup.3 g/mol) made by polycondensation and the
oligomers were dried in a vacuum at 60.degree. C. overnight. The
oligomers were heated (further polymerized) at 140.degree. C. for 1
hour. After that, the flask was cooled down and about 15 mg of tin
catalyst was added. The flask was transferred to Kugelrohr for
depolymerization of the oligomer at 200.degree. C. for 2 hours and
under a vacuum (500 mTorr-1 Torr). The distillates were collected.
Both of the distillates and the mixture in the flask were analyzed
by HPLC and GPC. The distillates had cyclic dimers with 90.7%
purity by HPLC, yield 0.62 grams. The cyclic dimer concentration in
the reaction mixture was 4.3%. An estimation of cyclic dimer yield
in this reaction was 18%. An HPLC spectrum of the distillates is
shown in FIG. 8.
* * * * *