U.S. patent application number 12/646521 was filed with the patent office on 2010-04-22 for generation of endo- and/or exo-norbornenecarboxaldehyde as an intermediate to functionalized norbornenes.
This patent application is currently assigned to PROMERUS LLC. Invention is credited to Andrew Bell, Dietrich Fabricius, Dane Jablonski, Brian Knapp, Peter Wyatt Newsome.
Application Number | 20100099906 12/646521 |
Document ID | / |
Family ID | 40588813 |
Filed Date | 2010-04-22 |
United States Patent
Application |
20100099906 |
Kind Code |
A1 |
Bell; Andrew ; et
al. |
April 22, 2010 |
GENERATION OF ENDO- AND/OR EXO-NORBORNENECARBOXALDEHYDE AS AN
INTERMEDIATE TO FUNCTIONALIZED NORBORNENES
Abstract
Embodiments in accordance with the present invention provide for
forming essentially pure diastereomers of 5/6-substituted
norbornene-type monomers. Further, embodiments in accordance with
the present invention encompass polymerizing such diastereomers to
form addition or ROMP polymers where a desired exo-/endo-ratio of
the diastereomers is provided to the polymerization, such ratio
designed to provide a desired ratio of endo-/exo-structured
repeating units for a resulting polymer to have desired physical or
chemical properties.
Inventors: |
Bell; Andrew; (Lakewood,
OH) ; Knapp; Brian; (Medina, OH) ; Jablonski;
Dane; (Brunswick, OH) ; Fabricius; Dietrich;
(Hendersonville, NC) ; Newsome; Peter Wyatt;
(Horse Shoe, NC) |
Correspondence
Address: |
TUROCY & WATSON, LLP
127 Public Square, 57th Floor, Key Tower
CLEVELAND
OH
44114
US
|
Assignee: |
PROMERUS LLC
Brecksville
OH
|
Family ID: |
40588813 |
Appl. No.: |
12/646521 |
Filed: |
December 23, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12262924 |
Oct 31, 2008 |
7662996 |
|
|
12646521 |
|
|
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|
60985393 |
Nov 5, 2007 |
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Current U.S.
Class: |
558/428 |
Current CPC
Class: |
C07C 51/16 20130101;
C07C 29/14 20130101; C07C 51/285 20130101; C07C 2602/42 20170501;
C07C 51/29 20130101; C07C 29/14 20130101; C07C 31/278 20130101;
C07C 61/13 20130101; C07C 47/347 20130101; C07C 31/38 20130101;
C07C 61/13 20130101; C07C 61/13 20130101; C07C 45/44 20130101; C07C
45/44 20130101; C07C 51/29 20130101; C07C 51/285 20130101; C07B
2200/09 20130101; C07C 51/16 20130101; C07C 29/14 20130101 |
Class at
Publication: |
558/428 |
International
Class: |
C07C 255/52 20060101
C07C255/52 |
Claims
1. A method for forming essentially pure exo- and/or
endo-substituted polycyclic olefin monomers, comprising: forming a
diastereomeric mixture of norbornenecarbonitrile (NBCN) via a
Diels-Alder reaction; separating the endo- and exo-diastereomers of
such diastereomeric mixture; selecting one of the exo- or
endo-diastereomers and contacting such selected diastereomer with
cyclopentadiene to form the selected tetracyclododecenecarbonitrile
(TDCN); first converting such selected TDCN to a
tetracyclododecenecarbaldehyde (TDCHO); and second converting the
TDCHO to one of a tetracyclododecene carboxylic acid (TDCO.sub.2H)
or a tetracyclododecene methyl alcohol (TDCH.sub.2OH).
2. The method of claim 1, where selecting comprises selecting the
exo-diastereomer.
3. The method of claim 1, where the first converting comprises
charging a reaction vessel with a metal hydride and the selected
TDCN diastereomer to effect a reduction of such TDCN diastereomer
and subsequently hydrolysing the reaction intermediate.
4. The method of claim 1, where the second converting comprises
charging a reaction vessel with a hydride donor reagent and an
individual exo- or endo-carboaldehyde containing diastereomer to
effect a reduction of the exo- or endo-carboaldehyde containing
diastereomer.
5. The method of claim 1, where the second converting comprises
charging a reaction vessel with an appropriate oxidizing agent and
an individual exo- or endo-carboaldehyde containing diastereomer to
effect an oxidation of the exo- or endo-carboaldehyde containing
diastereomer.
6. The method of claim 3, where the second converting comprises
charging a reaction vessel with an appropriate oxidizing agent and
an individual exo- or endo-carboaldehyde containing diastereomer to
effect an oxidation of the exo- or endo-carboaldehyde containing
diastereomer.
7. The method of claim 3, where the second converting comprises
charging a reaction vessel with an appropriate reducing agent and
an individual exo- or endo-carboaldehyde containing diastereomer to
effect a reduction of the exo- or endo-carboaldehyde containing
diastereomer.
8. The method of claim 3, where the second converting comprises
charging a reaction vessel with a hydride donor reagent and an
individual exo- or endo-carboaldehyde containing diastereomer to
effect a reduction of the exo- or endo-carboaldehyde containing
diastereomer.
9. The method of claim 3, where the metal hydride comprises lithium
aluminum hydride, alkyl aluminum hydrides, alkoxyaluminum hydrides,
or dialkylamino lithium hydrides.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority to U.S.
Provisional Application Ser. No. 60/985,393 filed Nov. 5, 2007, the
entire contents of which are hereby incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates generally to the preparation
of functionalized exo- and/or endo-norbornene-type monomers and
more specifically to methods for the preparation of endo- and/or
exo-norbornenecarboxaldehyde and of the aforementioned
functionalized monomers therefore.
DETAILED DESCRIPTION
[0003] The reactivity of 4/5 substituted norbornene (NB) monomers
employed in addition polymerization (AP) and ring-opening
metathesis polymerization (ROMP) has been found to depend, in part,
on the relative concentration of the exo monomer in the monomer
starting material and the spacing of the functional group (FG)
portion of the 4/5 substituent from the monomer's bicyclic
structure portion. While synthetic routes to generate
diastereomerically pure endo- and/or exo-functionally substituted
norbornene monomers (NBFG) are known, none are routine methods that
begin from a generally available feedstock. Therefore it would
advantageous to have one or more such routine, cost effective
methods for the forming of such diastereomerically pure endo-
and/or exo-NBFG monomers.
[0004] Exemplary embodiments in accordance with the present
invention will be described herein below. Various modifications,
adaptations or variations of such exemplary embodiments may become
apparent to those skilled in the art as such embodiments are
disclosed. It will be understood that all such modifications,
adaptations or variations that rely upon the teachings of the
present invention, and through which these teachings have advanced
the art, are considered to be within the scope and spirit of the
present invention.
[0005] For example, while the examples provided herein are
presented to demonstrate some embodiments in accordance with the
present invention that make use of essentially pure exo- and
endo-norbornenecarboxaldehyde (NBCA) to create norbornene monomers
having other function groups, such examples are not exhaustive of
all possible reactions that can make use of a NBCA intermediate.
However, such other reactions, being generally known, are believed
to be within the scope and spirit of the present invention.
[0006] Other than in the operating examples, or where otherwise
indicated, all numbers, values and/or expressions referring to
quantities of ingredients, reaction conditions, etc., used in the
specification and claims are to be understood as modified in all
instances by the term "about."
[0007] Various numerical ranges are disclosed in this patent
application. Because these ranges are continuous, unless
specifically noted otherwise, they include the minimum and maximum
values of each range and every value therebetween. Furthermore,
unless expressly indicated otherwise, the various numerical ranges
specified in this specification and in the claims are
approximations that are reflective of the various uncertainties of
measurement encountered in obtaining such values.
[0008] As used herein, "hydrocarbyl" refers to a radical of a group
that contains only carbon and hydrogen, non-limiting examples being
alkyl, cycloalkyl, aryl, aralkyl, alkaryl, and alkenyl. The term
"halohydrocarbyl" refers to a hydrocarbyl group where at least one
hydrogen has been replaced by a halogen. The term "perhalocarbyl"
refers to a hydrocarbyl group where all hydrogens have been
replaced by halogens. In addition, in some embodiments in
accordance with the present invention, the terms hydrocarbyl,
halohydrocarbyl or perhalocarbyl can encompasses one or more
heteroatoms such as O, N, S and Si. Exemplary groups encompassing
heteroatoms include, among others, a maleimide group, a
triethoxysilyl group, a trimethoxysilyl group, a methyl acetate
group, a hexafluoroisopropyl alcohol group, a
trifluoromethanesulfonamide group and a t-butylcarboxylate
group.
[0009] As used herein, "alkyl" refers to a linear or branched
acyclic or cyclic, saturated hydrocarbon group having a carbon
chain length of, for example, from C.sub.1 to C.sub.25. Nonlimiting
examples of suitable alkyl groups include, but are not limited to,
--CH.sub.3, --(CH.sub.2).sub.2CH.sub.3, --(CH.sub.2).sub.4CH.sub.3,
--(CH.sub.2).sub.5CH.sub.3, --(CH.sub.2).sub.10CH.sub.3,
--(CH.sub.2).sub.23CH.sub.3.
[0010] As used herein the term "aryl" refers to aromatic groups
that include, without limitation, groups such as phenyl, biphenyl,
benzyl, tolyl, dimethylphenyl, xylyl, naphthalenyl, anthracenyl and
the like, as well as heterocyclic aromatic groups that include,
without limitation, pyridinyl, pyrrolyl, furanyl, thiophenyl and
the like.
[0011] As used herein, "alkenyl" refers to a linear or branched
acyclic or cyclic hydrocarbon group having one or more double bonds
and having an alkenyl carbon chain length of C.sub.2 to
C.sub.25.
[0012] As used herein the terms "alkaryl" or "aralkyl" refer to a
linear or branched acyclic alkyl group substituted with at least
one aryl group, for example, phenyl, and having an alkyl carbon
chain length of C.sub.2 to C.sub.25.
[0013] Any of the aforementioned groups can be further substituted,
if desired. Such substituents can include a functional group (FG)
or moiety such as hydroxyl groups, carboxylic acid and carboxylic
acid ester groups. Also, such groups as a halogen other than
fluorine (Cl, Br, I), a nitrile (C.ident.N), amine (NR.sub.2 where
each R is independently hydrogen or hydrocarbyl), tosylate
(--SO.sub.2--C.sub.6H.sub.5--CH.sub.3, Ts) mesylate
(--SO.sub.2--CH.sub.3, Ms), acid chloride (--C(O)--Cl), or amide
(--C(O)--NR.sub.2, where at least one R is hydrogen) and the like
are also advantageous substituents for the aforementioned
groups.
[0014] As used herein reference to norbornene carboxylic acid
derivatives include, but are not limited to, esters, amides,
imines, acid halides and the like. In addition, reference herein to
norbornene alcohol derivatives include, but are not limited to,
ethers, epoxides, protected alcohols such as esters, and like.
Still further, reference above to substituted hydrocarbyls is also
inclusive of the carboxylic acids, and derivatives, and the
alcohols, and derivatives, defined above. Thus, as used herein, the
term "functional group" of "FG" will be understood to mean a
substituent other than a hydrocarbyl.
[0015] As used herein, the term "essentially pure," "pure," or
"high purity" when referring to, for example a monomer, a polymer
or diastereomer of some embodiments of the present invention, means
that the purity of such material is at least 95%. In other
embodiments such terms mean that the purity of such materials is at
least 98%, and in still other embodiments such terms mean that the
purity of such materials is 99% or greater.
[0016] As used herein, the term "transition metal polymerizations"
is used as a generic term to mean either addition polymerization
(AP) or ring opening metathesis polymerization (ROMP).
[0017] For some embodiments in accordance with the present
invention, it has been found that employing either an essentially
pure exo-monomer or an essentially pure endo-monomer as feedstock
for addition polymerization provides several advantages over using
diastereomeric mixtures of such monomers. For example, as compared
to diastereomeric mixtures, the addition polymerization of
essentially pure exo-monomers result in (i) improved monomer to
polymer conversion, (ii) reduced polymerization times, (iii) lower
catalyst loadings and (iv) enhanced control of polymer homogeneity.
Where either essentially pure endo- or exo-monomers are employed as
feedstock for addition polymerization enhanced control of polymer
homogeneity is also observed. Additionally, the polymerization of
single diastereomers can facilitate the tailoring of some polymer
properties. For example, generally a property such as the
dissolution rate of a polymer formed from an essentially pure exo
diastereomer is different from such rate for a polymer formed from
the analogous essentially pure endo diastereomer, thus where a
specific dissolution rate is desired, embodiments in accordance
with the present invention allow the mixing of appropriate amounts
of each isomer to obtain a specific dissolution rate.
[0018] Therefore it should be appreciated that in some transition
metal polymerizations, it can be advantageous to perform such
polymerizations using monomer feedstock that is an essentially pure
diastereomer, while in other polymerizations a mixture of the
diastereomers having a specific ratio might be desirable. It should
also be realized that although an all exo-NB monomer feedstock will
generally give the highest reactivity, and an all endo-NB monomer
feedstock will generally give the lowest reactivity, in systems
where a copolymer is being formed from functionally different
norbornene-type monomers the relative reaction rates of such
different monomers may require the matching of an endo to exo
isomer ratio in the feedstock to maintain the appropriate
reactivity control and achieve the desired isomer ratio in the
polymer being formed. It follows then that it is advantageous to
have the ability to formulate any desired exo/endo monomer reactant
ratio for the transition metal polymerization of such monomers, and
maintain this reactant ratio through either a continuous or
semi-batch metering strategy.
[0019] Some embodiments of in accordance with the present invention
are therefore directed to methods for forming essentially pure exo-
and/or endo-NB monomers in accordance with Formula I:
##STR00001##
[0020] where m is an integer from 0 to 3 and each occurrence of
R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently represents
hydrogen, a hydrocarbyl or a functional group (FG) substituent.
[0021] When any of R.sup.1 to R.sup.4 is a hydrocarbyl group, such
group can be a C.sub.1 to C.sub.30 alkyl, aryl, aralkyl, alkaryl,
alkenyl, alkynyl, cycloalkyl, cycloalkenyl, alkylidenyl or
alkylsilyl group. Representative alkyl groups include, but are not
limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl,
sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl,
nonyl, decyl and dodecyl. Representative alkenyl groups include,
but are not limited to, vinyl, allyl, butenyl and cyclohexenyl.
Representative alkynyl groups include, but are not limited to,
ethynyl, 1-propynyl, 2-propynyl, 1-butynyl and 2-butynyl.
Representative cycloalkyl groups include, but are not limited to,
cyclopentyl, cyclohexyl and cyclooctyl substituents. Representative
aryl groups include, but are not limited to, phenyl, tolyl,
dimethylphenyl, naphthyl and anthracenyl. Representative aralkyl
groups include, but are not limited to, benzyl and phenethyl.
Representative alkylidenyl groups include, but are not limited to,
methylidenyl, ethylidenyl, propylidenyl, and isopropylidenyl
groups. In addition, it should be noted that the hydrocarbyl groups
mentioned above can themselves be substituted, that is to say one
of the hydrogen atoms can be replaced, with linear and/or branched
C.sub.1-C.sub.10 alkyl, haloalkyl and perhaloalkyl groups, aryl
groups and cycloalkyl groups and or include one or more heteroatoms
such as O, N, S or Si, among others.
[0022] Any of R.sup.1 to R.sup.4 can also be a halohydrocarbyl
group, where such group includes any of the hydrocarbyls mentioned
above where at least one, but less than all, of the hydrogen atoms
of the hydrocarbyl are replaced by a halogen (fluorine, chlorine,
bromine or iodine). Additionally, any of R.sup.1 to R.sup.4 can be
a perhalocarbyl, where such group includes any of the hydrocarbyls
mentioned above where all of the hydrogen atoms of the hydrocarbyl
are replaced by a halogen. Useful perfluorinated substituents
include, but are not limited to, perfluorophenyl, perfluoromethyl,
perfluoroethyl, perfluoropropyl, perfluorobutyl and
perfluorohexyl.
[0023] When the pendant group(s) is a FG substituent, any of
R.sup.1 to R.sup.4 independently represent a linear or branched
carboxylic acid, carboxylic acid ester, ether, alcohol and carbonyl
groups. Representative examples of such substituents are functional
substituents that include, but are not limited to, radicals
selected from --(CR*.sub.2).sub.n--C(O)OR.sup.5,
--(CR*.sub.2).sub.n--OR.sup.5, --(CR*.sub.2).sub.n--C(O)R.sup.5,
--(CR*.sub.2).sub.nSiR.sup.5,
--(CR*.sub.2).sub.nSi(OR.sup.5).sub.3,
A-O--[--(C(R.sup.5).sub.2).sub.n--O--].sub.n--(C(R.sup.5).sub.2).sub.n--O-
H and R.sup.5(Z), where each n independently represents an integer
from 0 to 10, R* can be hydrogen or halogen and each R.sup.5
independently represents hydrogen, a halogen, a C.sub.1 to C.sub.30
alkyl, aryl, aralkyl, alkaryl, alkenyl, alkynyl, cycloalkyl,
cycloalkenyl and alkylidenyl group, that can also contain one or
more hetero atoms. Further, A is a linking group selected from a
C.sub.1 to C.sub.6 linear, branched, or cyclic alkylene, and Z is a
functional group selected from hydroxyl, carboxylic acid, amine,
thiol, isocyanate and epoxy. Representative hydrocarbyl groups set
forth under the definition of R.sup.5 is the same as those
identified above under the definition of R.sup.1 to R.sup.4.
Further, R.sup.5 can represent a moiety selected from
--C(CH.sub.3).sub.3, --Si(CH.sub.3).sub.3,
--CH(R.sup.6)OCH.sub.2CH.sub.3, --CH(R.sup.6)OC(CH.sub.3).sub.3 or
the following cyclic groups:
##STR00002##
[0024] where R.sup.6 represents hydrogen or a linear or branched
(C.sub.1-C.sub.5) alkyl group. Such alkyl groups include methyl,
ethyl, propyl, i-propyl, butyl, i-butyl, t-butyl, pentyl, t-pentyl
and neopentyl. In the above structures, the single bond line
projecting from the cyclic groups indicates the position where the
cyclic group is bonded to any of the aforementioned
R.sup.5-containing substituents. Further examples of R.sup.6
radicals include 1-methyl-1-cyclohexyl, isobornyl,
2-methyl-2-isobornyl, 2-methyl-2-adamantyl, tetrahydrofuranyl,
tetrahydropyranoyl, 3-oxocyclohexanonyl, mevalonic lactonyl,
1-ethoxyethyl and 1-t-butoxy ethyl.
[0025] R.sup.5 can also represent dicyclopropylmethyl (Dcpm), and
dimethylcyclopropylmethyl (Dmcp) groups which are represented by
the following structures:
##STR00003##
[0026] In some embodiments employing monomers in accordance with
Formula I, the perhalohydrocarbyl groups can include perhalogenated
phenyl and alkyl groups. In other embodiments, the perfluorinated
substituents can include perfluorophenyl, perfluoromethyl,
perfluoroethyl, perfluoropropyl, perfluorobutyl and perfluorohexyl.
In addition to the halogen substituents, cycloalkyl, aryl and
aralkyl groups of such embodiments can be further substituted with
linear and branched C.sub.1-C.sub.5 alkyl and haloalkyl groups,
aryl groups and cycloalkyl groups. Non-limiting examples of such
monomers include structural formulae depicted in Structural Groups
MM, NN and PP.
[0027] In other embodiments, polycyclic olefin monomers include,
but are not limited to, 5-norbornene-2-methanol hydroxylethylether,
t-butyl ester of 5-norbornene 2-carboxylic acid, hydroxyethylester
of 5-norbornene carboxylic acid, trimethylsilane ester of
5-norbornene carboxylic acid, 5-norbornene-2-methanol acetate,
5-norbornene-2-methanol, 5-norbornene-2-ethanol,
5-triethoxysilylnorbornene, 1-methylcyclopentyl ester of
5-norbornene carboxylic acid, tetrahydro-2-oxo-3-furanyl ester of
5-norbornene carboxylic acid and mixtures thereof.
[0028] In still other embodiments, at least one of R.sup.1 and
R.sup.4 of Formula I is a QNHSO.sub.2R.sup.8 group or a
Q.dagger-dbl.(CO)O--(CH.sub.2).sub.m--R.sup.8 group, where Q a
linear or branched alkyl spacer of 2 to 5 carbons and Q.dagger-dbl.
is an optional linear or branched alkyl spacer of 1 to 5 carbons, m
is either 0 or an integer from 1 to 3, inclusive, and R.sup.8 is a
perhalo group of 1 to about 10 carbon atoms. The others of R.sup.1
to R.sup.4 are each generally hydrogen.
[0029] In yet other embodiments, at least one of R.sup.1 to R.sup.4
is one of groups AA, BB or CC, and the others are each generally
hydrogen (please note that each of the representations of
functional groups AA through KK and KJH can be either exo- or an
endo-substituted):
##STR00004##
[0030] where each in is defined as above and independently
selected, Q.dagger-dbl. is also as defined above, Q* is a linear or
branched alkyl spacer of 1 to 5 carbons and A is an a linear or
branched alkyl spacer of from 1 to 8 carbons. In some embodiments
encompassing groups AA or CC, Q.dagger-dbl. is not present or is a
linear alkyl spacer of 1 to 3 carbons. Additionally, for group CC,
Q* can be a linear or branched spacer of 3 or 4 carbons. In other
such embodiments, Q.dagger-dbl. is not present or is 1 carbon atom.
In other embodiments encompassing group BB, m is either 1 or 2. In
exemplary embodiments of the encompassing repeating units
represented by Formula I, one of R.sup.1 to R.sup.4 is group BB
while the others are each hydrogen, n is 0 and each m is 1.
[0031] In yet other embodiments, at least one of R.sup.1 to R.sup.4
of Formula I is one of groups DD, EE or FF, and the others are each
generally hydrogen:
##STR00005##
[0032] where each X is independently either fluorine or hydrogen,
each q is independently an integer from 1 to 3, p is an integer
from 1 to 5, Q* is as defined above, and Z is a linear or branched
halo or perhalo spacer of 2 to 10 carbons. In some embodiments
encompassing group DD, Q* is a single carbon spacer, X is fluorine,
q is 2 or 3 and p is 2. In some embodiments encompassing group EE,
Q* is a single carbon spacer and Z is a branched fluorinated alkyl
chain of up to 9 carbons units. In some embodiments encompassing
group FF, Q* is a single carbon spacer and q is 1 or 2.
[0033] In other embodiments, at least one of R.sup.1 to R.sup.4 is
a group represented by the formula GG, and the others are each
generally hydrogen:
##STR00006##
[0034] where Q.dagger-dbl., if present, is an optional linear or
branched alkyl spacer where of 1 to 5 carbons. In some other
embodiments one of R.sup.1 to R.sup.4 is a group represented by
formula GG, each of the others is hydrogen and Q.dagger-dbl. is not
present or is a linear alkyl spacer of 1 to 3 carbons.
[0035] In other embodiments in accordance with Formula I, at least
one of R.sup.1 to R.sup.4 is a group represented by one of HH, JJ
or KK shown below, and the others are each generally hydrogen:
##STR00007##
[0036] where Q.dagger-dbl. is as defined above and R.sup.9 is a
linear or branched alkyl group of 1 to about 5 carbon atoms. It
should be noted that the HJK(acid) group represented above, is
derived from one of the H, J or K groups.
[0037] The monomer compositions employed for embodiments in
accordance with the present invention can include any one or
multiple variations of the polycyclic olefin monomers of Formula I.
Thus, polymers formed by embodiments in accordance with the present
invention can encompass homopolymers and polymers that incorporate
any monomer that is in accordance with Formula I. Exemplary
monomers in accordance with Formula I are depicted in Structural
Groups MM, NN and PP shown below, where any of such monomer
representations is understood to depict both the exo- and
endo-isomer:
##STR00008## ##STR00009## ##STR00010## ##STR00011##
[0038] As mentioned above, all of the functional groups AA through
KK and KJH are inclusive of either an exo- or endo-substituted
group as are the substituents shown in Monomers MM, NN or PP and
thus are consistent with the generic representations Formula IIa
and IIb:
##STR00012##
[0039] where FG represents a functional group and is one of
R.sup.1, R.sup.2, R.sup.3 or R.sup.4 of Formula I and m is 0.
[0040] For some embodiments in accordance with the present
invention, the monomers of Formula IIa and IIb are further
subjected to a Diels-Alder reaction with cyclopentadiene (CPD) to
generate a CPD homolog, such as tetracyclododecene-type monomers (m
of Formula I is 2). In other embodiments m of Formula I can be 3 or
larger via a similar reaction with CPD. As one of skill in the
should know, the products of such a Diels-Alder reaction is
governed by, in pertinent part, the sterics of both the CPD and the
NBFG, therefore where the NBFG is a pure exo-monomer, it will will
yield different compositions of the polycyclic rings than where the
NBFG is a pure endo-NBFG monomer, as shown below. In some cases,
there is an enhanced reaction and improved yield for the TD
molecules when exo-NBFG is employed as a reactant.
##STR00013##
[0041] Referring now the Reaction Schemes that follow, it has been
found advantageous to generate 5-norbornenecarbonitrile (5-NBCN or
NBCN) as a first step to the forming of high purity exo-NBFG and
endo-NBFG monomers. The Diels-Alder reaction to form the NBCN is
thus shown as Step 1 of the Reaction Schemes. The benefit of such a
first step is first, such a reaction results in a diastereomeric
mixture having a ratio of endo to exo isomers of about 55:45 so
that, advantageously, about equal amounts of each isomer is present
in the mixture; and second that while most diastereomeric mixtures
are difficult to separate, the NBCN isomers (also referred to
herein as diastereomers or epimers) can be successfully separated
by fractional distillation. It should be noted that the conditions
under which such a distillation is performed should be carefully
controlled such that the separation can be cost effective and high
yielding both with regard to the starting ratio of isomers and with
regard to the isomeric purity of the individual endo- and/or
exo-isomers.
[0042] Once the individual endo- and exo-NBCN isomers are
separated, each can be reduced to the analogous endo- or
exo-norbornene-5-carboxaldehyde isomer (Step 2), for example by
partial reduction to an imine and hydrolysis to the aldehyde. In
general, this method involves using a metal hydride reducing agent
to add 1 mol of hydrogen for the reduction to the imine and
hydrolysis, in situ, to form the aldehyde. Appropriate reducing
agents include, but are not limited to, lithium aluminum hydride
(LiAlH.sub.4), alkyl aluminum hydrides (e.g. diisobutylaluminum
hydride (DIBAL-H)), alkoxyaluminum hydrides (e.g. lithium
triethoxyaluminum hydride (LiAlH(OEt).sub.3)), and dialkylamino
lithium hydrides (e.g. lithium tris(diethylamino)aluminum hydride
(LiAlH(NEt.sub.2).sub.3)). As shown in Steps 3-13 of the Reaction
Schemes, first forming either a desired exo- or
endo-5-carboxaldehydeNB (NBCHO) provides an advantageous starting
point for the forming of a broad range of exo- and endo-NBFG
monomers.
[0043] For ease of understanding and display, such Reaction Schemes
depict only the exo-NBFG monomer for each step (except for Step 13
where only the endo isomer has, to date, been twined), however it
will be understood that where the endo-NBCHO is used as a starting
point, the NBFG monomers formed will be an endo-monomer. In the
Examples included herein, an exemplary reaction for each of Steps
1-13 is provided. It should be noted that these exemplary reactions
are non-limiting as the use of reagents other than those disclosed
can also be effective for forming a desired essentially pure exo-
or endo-NBFG monomer.
[0044] Still referring to the Reaction Schemes, the advantage of
forming the NBCHO epimers from the analogous NBCN epimers should be
recognized as (1) forming NBCN via a Diels-Alder reaction provides
nearly equal amounts of each isomer, (2) the separation of such
NBCN isomers can be effectively accomplished via distillation, and
(3) the reduction of such NBCN isomers to the corresponding NBCHO
isomer using an appropriate aluminum hydride is essentially
quantitative. Further to this advantage is that the resulting NBCHO
isomers are readily transformed to the corresponding carboxylic
acid (via an appropriate oxidizing reagent) or alcohol (via an
appropriate hydride donor reagent) thus providing facile pathways
to a wide variety of functionalized NB monomers without losing the
isomeric purity obtained through the initial separation of the NBCN
isomers. In contrast the direct acid or base treatments of nitriles
to form the analogous carboxylic acids generally results in the
epimerization of the diastereomers. Therefore, embodiments in
accordance with the present invention provide a significant
advantage in comparison with previously known methods.
[0045] Said in a different manner, embodiments in accordance with
the present invention allow for forming either an alcoholic
functionalized NB monomer of high isomeric purity or a carboxylic
acid functionalized NB monomer of high isomeric purity. Such
alcoholic functionalized monomers can be used to form derivatives
having functional groups such as --CH.sub.2OAc,
--CH.sub.2OCH.sub.2C(CF.sub.3).sub.2OH (via hexafluoroisobutylene
oxide), --CH.sub.2Cl, --CH.sub.2Br, --CH.sub.2I,
--CH.sub.2NH.sub.2, --CH.sub.2O Ms, --CH.sub.2OTs and
--CH.sub.2C(CF.sub.3).sub.2OH. In addition, such embodiments
provide for the use of a variety of coupling reactions to expand
the above list of possible functional groups significantly, such
reactions including, but not limited to, the Kumada, Sonogashira,
Heck, Stille, Suzuki, Hiyama and Negishi reactions. Further, the
carboxylic acid functionalized isomers can be subjected to standard
organic synthesis derivatization methods to generate ester
functionalized materials, for example, some of the materials shown
above as Structures MM. Still further where an alcoholic
functionalized isomer is converted to a chloro, bromo or iodo
diastereomer, such can be employed in sp.sup.3-sp,
sp.sup.3-sp.sup.2, and sp.sup.3-sp.sup.3 coupling and
organometallic reactions (e.g. formation of Grignards, organo
lithiums, organo zincs, organo cuprates and organo stannanes). In
one particular noteworthy example, exo-NBCH.sub.2I (or
endo-NBCH.sub.2I) can be used to generate an organozinc iodide at
moderate temperatures. Advantageously, it has been found that such
an organozinc iodide reacts smoothly with hexafluoroacetone to
generate the appropriate exo- or endo-HFANB in high yield (about
70%) and high diastereomeric purity.
[0046] While not specifically shown, embodiments in accordance with
the present invention encompass a homologation reaction of an
essentially pure exo- or endo-NBFG that provides for an overall
increase of the carbon skeleton of the functional group. For
example where the FG is an aldehyde or ketone, a reaction with
diazomethane or methoxymethylenetriphenylphosphine effectively
inserts a methylene (--CH.sub.2--) unit in the hydrocarbon chain of
the FG providing the next homolog. Other exemplary homologation
reactions that are encompassed by embodiments of the present
invention include, among others, (i) Seyferth-Gilbert homologation,
i.e., displacement of a halide by a cyanide group, which can be
reduced to an amine; (ii) Wittig reaction of an aldehyde with
methoxymethylene triphenylphosphine, which produces a homologous
aldehyde; (iii) Arndt-Eistert synthesis is a series of chemical
reactions designed to convert a carboxylic acid to a higher
carboxylic acid homolog (i.e., contains one additional carbon atom)
and (iv) Kowalski ester homologation which is a chemical reaction
for the homologation of esters. For some embodiments of the present
invention, reactions that increase the chain length of the FG by
more than one unit can also be employed. For example, the
nucleophilic addition of ethylene oxide results in a ring-opening
that produces a primary alcohol with two extra carbons.
[0047] The endo and exo-NBFG monomers that are useful in such
homologation reactions are NBCH.sub.2X (X.dbd.Br, Cl, I, OMs, and
OTs), NBCO.sub.2R, NBCO.sub.2H, NBCH.sub.2OH, and NBCH.sub.2C(O)R,
and NBCN. Specifically, exo-NBCO.sub.2H can be converted to
exo-NBCH.sub.2CO.sub.2H which in turn can be reduced to
exo-NBCH.sub.2CH.sub.2OH, which can be employed in preparing
exo-NBCH.sub.2CH.sub.2FG monomers.
[0048] Thus, embodiments in accordance with the present invention
encompass the forming of diastereomerically pure carboxaldehyde
building blocks (e.g. exo-NBCHO and endo-NBCHO, which can be
transformed into a multitude of derivatives that are important for
polymer applications and small molecule transformations. The
organic transformations of functional groups into new functional
groups include, among others, oxidation, reduction, homologation,
Wittig, amination, reductive aminations, esterification,
hydrogenation, hydrolysis, alcoholysis (acetal formation),
condensation (e.g. aldol), alkylation, arylation and transition
metal catalyzed reactions. However, it should be noted that while
there are a large number of common organic transformations that can
be employed by embodiments in accordance with the present
invention, not all such transformations are effective; hence
judicious choice of reaction conditions and reagents is necessary
to preserve the nature of the norbornene double bond for use in a
subsequent polymerization. Where a specific transformation method
or product is desired, but would be likely to effect the nature of
the norbornene double bond, it has been found that the use of
protecting groups at the double bond can be effective to allow
completion of the desired transformation, Further still, it should
be noted that embodiments in accordance with the present invention
also encompass the separation of the diastereomeric mixtures of
bis-nitrile norbornenes, TDCN diastereomeric mixtures and such
mixtures of higher homologs of such norbornenes, for example where
m of Formula I is 3 or greater. Thus the transformations depicted
in the Reaction Schemes are generally representative for analogous
bis-nitrile and TD and higher materials.
[0049] Referring still to bis-norbornenecarbonitrile
diastereoisomers such exo- and endo-norbornene-type monomers are
exo,exo-norbornene-2,3-dicarbonitrile,
exo,endo-norbornene-2,3-dicarbonitrile, and
endo,endo-norbornene-2,3-dicarbonitrile, appropriately represented
by Formulae IIIa and IIIb and IIIc, respectively:
##STR00014##
[0050] Representative preparative methods of the pure diastereomers
of formulae IIIa, IIIb, and IIIc are described in the following
articles: (i) A contribution to the stereospecificity of [4+2]
cycloadditions, Prantl, et al. Tetrahedron Letters (1982), 23(11),
1139-42, (ii) Facile preparation of
trans-2,3-bis[(t-butylamino)methyl]norbornene. Wynne, et al.
Organic Preparations and Procedures International (2002), 34(6),
655-657, and (iii) Bromine addition to cyanonorbornene derivatives.
Kikkawa, et al. Bulletin of the Chemical Society of Japan (1972),
45(8), 2523-7.
[0051] It should be noted that since embodiments in accordance with
the present invention can readily provide both diastereomeric forms
of a large variety of functionalized norbornene-type monomers
appropriate planning of the polymerization of such monomers, makes
it possible to provide specific ratios of diastereomers to the
polymerization reaction (by mixing the pure diastereomers). Thus,
ones ability to tailor the properties of the resulting polymer is
enhanced as compared to not having such pure diastereomers. For
example, U.S. Pat. No. 7,341,816, entitled "Method of Controlling
the Differential Dissolution Rate of Photoresist Compositions,
Polycyclic Olefin Polymers and Monomers Used for Making Such
Polymers" to Rhodes, et al., teaches that the dissolution rate of
some polymers is related to the exo/endo ratio of functionalized
polymer repeating units. Such patent shows that polymers having a
high concentration of repeating units derived from exo-HFANB
exhibit a higher than expected dissolution rate in aqueous base
solutions than analogous polymers that have a lower concentration
of repeating units derived from exo-HFANB, the comparative polymers
having essentially the same molecular weight. Where such patent
teaches obtaining polymers of different isomeric ratios by
separating them via a distillation, embodiments of the present
invention provide for providing a specific ratio of isomers to the
polymerization such that the resultant polymer has a desired
characteristic (e.g. a high dissolution rate or a low dissolution
rate).
##STR00015##
EXAMPLES
[0052] The following examples are provided for illustrative
purposes only and are in no way restrictive or limiting with
respect to the scope and spirit of the embodiments in accordance
with the present invention that are claimed. Specific examples are
provided that demonstrate the formation of each of the monomers
shown in the Reaction Schemes above, as well as examples that
demonstrate further demonstrate the broad scope of the instant
invention. Further, for each of the following examples, the GC
analysis was done on a DB5 column, 30 meters in effective length
and having a 0.32 min ID and a 0.25 .mu.m film. The sample was
injected into an injection chamber maintained at 275.degree. C.
After injection the column was maintained at 55.degree. C. for one
minute and then heated to 170.degree. C.@5.degree. C./min. The
detector temperature was 325.degree. C. Specific retention times
are reported below where appropriate.
Preparation of Exo-/Endo-Norbornenecarbonitrile
(Exo-/Endo-Nbcn)
[0053] To a 20 liter Parr pressure-rated reactor flushed with N2,
6.8 kg (51.3 mol, 1.1 eq of cyclopentadiene) of dicyclopentadiene
was added. Next, 5.11 kg (96.3 mol, 1.0 eq) of acrylonitrile was
added. The reactor was flushed three times with N.sub.2, and then
heated over a period of 3.25 hours to a temperature of about
180.degree. C. It was observed that the pressure reached a peak of
about 100 psig during the initial 3.25 hours. The reaction mixture
was stirred for another 2 hours at about 180.degree. C. during
which time the pressure stabilized to about 11 psig. After cooling
to 25.degree. C., 11.81 kg of the reaction mixture was drained from
the reactor. GC analysis of the mixture indicated a 93.0% yield of
exo/endo norbornene carbonitrile (43.3%/56.6%) product. GC
retention time was 4.0 mM. (exo-NBCN), 4.7 min. (endo-NBCN).
Separation/Purification Exo-/Endo-Norbornenecarbonitrile
[0054] About 8 kg of exo/endo norbornene carbonitrile (NBCN) was
charged to a vacuum distillation apparatus consisting of an
appropriately sized still pot with heating mantle, a packed
distillation column (60 theoretical plates), a reflux splitter, a
water cooled condenser, a condensate receiver and a vacuum pump.
The still pot temperature was controlled by adjusting the heat
input to the heating mantle and system vacuum was controlled by
adjusting the vacuum pressure at the overhead receiver (see
Experimental Section below).
[0055] After transferring the NBCN to the still pot, the
distillation system vacuum was adjusted to the desired set point.
Heating of the still pot then proceeded until total reflux
conditions were established in the distillation column. The reflux
splitter was then started at the desired reflux ratio and
fractional distillation proceeded by periodically removing liquid
fractions from the overhead receiver. GC analysis was used to
determine composition of the overhead liquid fractions.
Distillation reflux ratio was adjusted as needed to affect
composition of the overhead stream. The initial overhead fractions
were enriched in "light" components, which were primarily
acrylonitrile (ACN), cyclopentadiene (CPD) and dicyclopentadiene
(DCPD). After removal of these "light" components, high purity
exo-NBCN was then separated from the remaining endo-NBCN. After
removal of "transition" fractions, high purity endo-NBCN was then
collected. The distillation process is terminated once the majority
of endo-NBCN has been removed from the still pot.
TABLE-US-00001 TABLE 1 Feed NBCN Still Pot Temperature: exo-NBCN
127.degree. C. endo-NBCN 125.degree. C. Overhead Temperature:
exo-NBCN 57.degree. C. endo-NBCN 85.degree. C. System Vacuum:
exo-NCNB 2.0 endo-NBCN 1.7 mmHg mmHg Reflux Ratio: exo-NBCN 30:1
endo-NBCN 5:1 (exo:endo ratio = 1:3)
[0056] Approximately 57% of the contained exo-NBCN in the starting
mixture was removed as high-purity (98% or greater) material.
Approximately 44% of the contained endo-NBCN in the starting
mixture was removed as high-purity (98% or greater) material. The
medium-purity fractions can be recycled to increase overall process
yields.
Preparation of Exo-Norbornene-5-carboxaldehyde (Exo-NBCHO)
[0057] A 12-Liter glass flask fitted with mechanical stirrer,
nitrogen gas inlet, thermowell, and septa-sealed addition funnel
was dried by heating to .about.120.degree. C. under a nitrogen
flush. The flask was cooled to room temperature before cannulating
7900 ml (11.79 moles) 1.5 M Diisobutylaluminum hydride (DIBAL-H) in
toluene via the addition funnel into the flask. The DIBAL-H
solution was cooled to -51.6.degree. C. before adding exo-NBCN
(1328 g, 11.14 mol) dropwise. The addition was completed within 2
hrs 24 min while the temperature ranged from -51.6 to -39.3.degree.
C. The mixture was stirred an additional 30 minutes. GC analysis
revealed no unreacted exo-NBCN remaining. The reaction mixture was
kept at -46 to -39.degree. C. while it was cannulated in eleven
500-ml portions into a dry ice/isopropanol-cooled jacketed addition
funnel. This was added rapidly dropwise in eleven 500-ml portions
to mechanically stirred 12.24 Liters of 3.5 N hydrochloric acid
chilled to -5.6.degree. C. with dry ice/acetonitrile. There is an
induction period, so the reaction exotherm was allowed to subside
before each subsequent addition of the DIBAL-H reaction mixture.
The temperature ranged from 5.6 to +0.1.degree. C. Quench time was
2 hours. MTBE (methyl tertiary butyl ether, 4000 ml) was added via
the chilled addition funnel. The mixture was stirred several
minutes, allowed to settle, and the phases separated. The aqueous
phase was extracted with 3.times.4000 ml MTBE. The organic portions
were combined, washed with 5000 ml 3.5 N hydrochloric acid, and
washed with 3.times.2 gallons brine until the final wash gave pH 6.
The MTBE/toluene solution was split and placed in seven bottles,
dried over sodium sulfate, and stored in a refrigerator overnight.
The mixture was filtered and rotary evaporated at 35.degree. C.
maximum bath temperature to yield 3173 g of product. NMR analysis
indicates 35.2 wt % NBCHO in toluene, giving 82% yield. GC analysis
gives an exo/endo ratio of 99.8/0.2. NBCHO is unstable and
epimerizes readily, therefore the solution was refrigerated for
future use. GC retention time was 2.05 min. (exo-NBCHO), 2.23 min.
(endo-NBCHO).
Preparation of Exo-Norbornene-5-methanol (Exo-NBCH.sub.2OH)
[0058] In a 22-Liter glass flask fitted with mechanical stirrer,
thermowell, nitrogen inlet, and addition funnel were placed 1880 ml
of 8% aqueous sodium hydroxide solution. NaBH.sub.4 (174.1 g, 4.6
mol) was added portion wise. The mixture was cooled to -7.4.degree.
C. Exo-NBCHO (3173 g at 35.2 wt % in toluene, .+-.9.17 mol total)
was dispensed just before use in 400 ml portions that were
dissolved in 600 ml methanol before adding dropwise to the sodium
borohydride solution. Addition time totaled 5.1 hours while
reaction temperature ranged from -7.1 to -0.8.degree. C.
Inconsistent GC analysis prompted the addition of another 35 g of
sodium borohydride. The reaction was stirred one hour while cooling
from -1.7 to -12.7.degree. C. GC analysis indicated <0.15%
unreacted NBCHO. 10% aqueous sulfuric acid (2200 ml) was added
dropwise over 1.5 hours while the temperature ranged from -11.4 to
+0.7.degree. C. Resulting pH was 6. Dichloromethane (3000 ml), 500
ml brine, and 2000 ml water were added and the mixture stirred
several minutes. The phases were separated. The remaining aqueous
phase was treated with 2000 ml dichloromethane, 2000 ml water, and
2000 ml brine. The dichloromethane phase was removed and the
aqueous phase again mixed with 2000 ml dichloromethane, 2000 ml
water, and 2000 ml brine. The dichloromethane phase was removed and
the aqueous phase treated with 2000 ml dichloromethane and 2000 ml
water. The dichloromethane extracts were combined, the residual
water was separated, and the organic portion then dried over sodium
sulfate overnight. After filtration, the extracts were rotary
evaporated to give 1210 g yellow liquid (87% yield from NBCHO).
[0059] The material was vacuum distilled, giving the following
fractions: [0060] I. 34.6-109.4.degree. C. (12-20 Torr), 46.2 g,
hazy, 60.3% NBMeOH and 39.7 wt % toluene [0061] II.
106.3-100.7.degree. C. (5-8 Torr), 172.5 g, 98.5% exo-NBMeOH, 1.3%
endo-NBMeOH, no toluene [0062] III. 81.4-93.2.degree. C. (2-3
Torr), 236.7 g, 99.3% exo-NBMeOH, 0.7% endo-NBMeOH, no toluene
[0063] IV. 62.2-69.4.degree. C. (1-2 Torr), 578.1 g, 99.1%
exo-NBMeOH, 0.9% endo-NBMeOH [0064] V. 63.1-68.5.degree. C. (1
Torr), 29.02 g, 99.5% exo-NBMeOH, 0.5% endo-NBMeOH.
[0065] The distillation pot residue was dissolved in .about.400 ml
dichloromethane and washed with 100 ml 10% sulfuric acid. The
resulting mixture was treated with 100 ml water to force phase
separation. The phases were separated. To the aqueous phase was
added 100 ml brine to force more dichloromethane out of the
solution. The dichloromethane portions were combined, washed with
5.times.100 ml brine to pH 6, and then dried over sodium sulfate.
The dried extract was filtered and rotary evaporated. This product
was vacuum distilled to give 37.7 g@60.8-65.1.degree. C. (1 Torr).
GC analysis showed 0.5% endo-isomer and 99.5% exo-isomer. A less
pure fraction of 37.31 g was collected at 63.1-65.2.degree. C. (2
Torr) containing 98.9% exo-isomer and 0.85% endo-isomer. Total
yield of >99.8% (total isomer) purity was 1058.5 g (76.5% yield
from NBCN, .about.93% yield from NBCHO). GC retention time: 2.82
minutes (endo-NBMeOH), 3.97 min (exo-NBMeOH).
Preparation of Endo-Norbornenecarboxaldehyde (Endo-NBCHO)
[0066] A 12-Liter glass flask fitted with mechanical stirrer,
nitrogen gas inlet, thermowell, and septa-sealed addition funnel
was dried by heating to .about.120.degree. C. under a nitrogen
flush. The flask was cooled to room temperature before cannulating
4970 ml (7.4 moles) 1.5 M DIBAL-H in toluene via the addition
funnel into the flask. The DIBAL-H solution was cooled to
-71.8.degree. C. Endo-NBCN (838 g, 7.0 mol) was melted, diluted
with 100 ml toluene, and added dropwise to the DIBAL-H solution.
The addition was completed within 2 hours while the temperature
ranged from -71.8 to -50.4.degree. C. GC analysis revealed no
unreacted endo-NBCN remaining. The reaction mixture was cannulated
in ten 500 ml portions into a dry ice/isopropanol-cooled jacketed
addition funnel. Each portion was then added dropwise to 8190 ml of
a mechanically stirred 3.5 N hydrochloric acid solution chilled to
-15.5.degree. C. with dry ice/acetonitrile. An induction period was
observed, so the reaction exotherm was allowed to subside before
each subsequent addition of the DIBAL-H reaction mixture. During
these additions, the temperature ranged from -35 to +1.0.degree. C.
Total quench time was about 2 hours. Next, MTBE (3000 ml) was added
via the chilled addition funnel, the mixture stirred for several
minutes, allowed to settle, and the phases separated. The aqueous
phase was extracted with 2.times.3000 ml MTBE. The organic portions
were combined, washed with 2500 ml 3.5 N hydrochloric acid, and
then washed with 7.times.1 gallon brine until the final wash showed
a pH of 7. The MTBE/toluene solution was split into four portions
and each was dried over sodium sulfate, and stored in an ice chest
overnight.
[0067] The next day, the mixture was filtered and rotary evaporated
at a maximum bath temperature of 35.degree. C. NMR analysis of the
residues indicated 25.0 wt % NBCHO in toluene with 9.2 wt %
residual MTBE. The product was concentrated further with rotary
evaporation and a second NMR analysis indicated 31.7% endo-NBCHO,
65.4% toluene, and 2.8% MTBE. GC analysis indicated the
endo-/exo-ratio to be 97.3/2.7. Yield was approximately 70%. Since
endo-NBCHO is unstable and epimerizes readily, the solution was
refrigerated until needed. GC retention time: 2.13 minutes
(exo-NBCHO), 2.33 (endo-NBCHO).
Preparation of Endo-Norbornenemethyl Alcohol
[0068] In a 5-L 4-neck flask fitted with mechanical stirrer,
thermowell, nitrogen inlet, and addition funnel were placed 360 ml
(0.72 mol) of 8% aqueous sodium hydroxide solution. NaBH.sub.4
(33.1 g, 0.88 mol) was added portionwise. The mixture was cooled to
-10.6.degree. C. Approximately one-half of endo-NBCHO solution
(558.1 g at 30.6 wt % in toluene, .about.1.39 mol total) was
diluted with 500 ml methanol and added dropwise. Addition time was
1.5 hrs while reaction temperature ranged from -11.4 to
-3.1.degree. C. The remaining endo-NBCHO solution was diluted with
500 ml methanol and added dropwise to the reaction mixture.
Addition was completed in 48 minutes with reaction temperature
ranging from -10.8 to -6.3.degree. C. GC analysis indicated 4.9%
endo-NBCHO remained. The mixture was stirred at -11.8 to
-5.6.degree. C. for 5 hrs 21 min. which allowed the endo-NBCHO
content to drop to 1.6%. Another 3.22 of sodium borohydride was
added and the mixture stirred another 1.5 hrs at -5.3 to
-13.5.degree. C. GC analysis showed 1.0% endo-NBCHO remaining. The
reaction flask was packed in ice and the mixture allowed to stir
overnight. The temperature had climbed only to 3.5.degree. C. and
GC analysis showed that only 0.4% endo-NBCHO remained.
[0069] The reaction was cooled to -11.5.degree. C. and 10% aqueous
sulfuric acid (390 ml) was added dropwise over 1.5 hrs while the
temperature ranged from -11.5 to +0.7.degree. C. At the end of the
addition the pH was 7. Another 100 ml of 10% sulfuric acid was
added to bring the pH to 2. Dichloromethane (500 ml) was added and
the mixture stirred vigorously. 100 ml brine and 300 ml water was
added, mixed thoroughly, and then allowed to settle. A large
emulsified interface resulted. The dichloromethane portion was
separated. Then 500 ml dichoromethane, 100 ml brine, and 300 ml
water were added to remaining aqueous phase. After mixing, the
dichloromethane phase was collected. Another 500 ml
dichloromethane, 100 ml brine, and 300 ml water was added to
aqueous phase and mixed. The dichloromethane phase was again
collected. The emulsion phase was collected and allowed to
separate. The resulting aqueous phase was removed and the remaining
emulsion treated with 500 ml brine. This gave a clean separation of
phases. The dichloromethane phase was removed, washed with 200 ml
brine to pH 6, and then combined with the previous dichloromethane
extracts. The combined dichloromethane extracts were washed with
3.times.400 ml brine to pH 7, dried over sodium sulfate, filtered
and rotary evaporated to 331.6 g. NMR indicates this is 59 wt %
endo-NBMeOH in toluene. NMR shows only a trace of exo-isomer. GC
analysis indicates an endo/exo ratio of 99:1.
[0070] The material was vacuum distilled through a 12-inch Vigreux
column, giving the following fractions: [0071] I. 25.1-19.0.degree.
C. (1.3-1.6 Torr), 11.86 g, 99.5% toluene [0072] II.
73.8-66.9.degree. C. (1.20-1.15 Torr), 28.79 g, 98.3% endo-NBMeOH,
contains 0.09% toluene [0073] III. 65.3-63.1.degree. C. (1.25-1.20
Torr), 99.64 g, 99.2% endo-NBMeOH, no toluene [0074] IV.
58.6-44.3.degree. C. (1.20-0.53 Torr), 47.87 g, 99.8% endo-NBMeOH
[0075] V. 47.2-42.2.degree. C. (0.62-0.57 Torr), 2.89 g, 99.4%
endo-NBMeOH.
[0076] Total yield of >99% endo-NBMeOH was 150.4 g (87%). Yield
based on endo-NBCN was 58%. NMR indicates 99.5% endo. GC Retention
time: 4.565 minutes (endo-NBMeOH), 4.599 minutes(exo-NBMeOH).
Preparation of Exo-Norbornenemethyl Acetate (Exo-NBMeOAc)
[0077] A 12-Liter glass flask, fitted with mechanical stirrer,
nitrogen inlet, addition funnel, and thermowell, was dried with a
hot air gun to 120.degree. C. under a nitrogen flush. After cooling
to room temperature, exo-norbornenemethanol (500.2 g, 4.0 mol) was
placed in the flask, followed by 4 Liters dry dichloromethane, 988
g (12.5 mol) dry pyridine, and another 2 Liters dry
dichloromethane. Dimethylaminopyridine (2.0 g, 16.5 mmol) was
added. Acetic anhydride was added rapidly within 30 minutes,
causing the reaction temperature to rise from 24.degree. C. to
41.degree. C. After 1.0 minutes, GC analysis indicated only 1.7%
starting material remained. After 2.5 hours, only 0.3% starting
material remained. An additional 22 ml of acetic anhydride was
added and the reaction mixture was allowed to stir overnight at
room temperature. GC analysis showed no further change in product
composition. The reaction was rotary evaporated to remove
dichloromethane and then rotary evaporated at 80.degree. C. to
remove excess pyridine and acetic anhydride. The residue, totaling
553 g, was vacuum distilled giving three fractions: [0078] I:
33.5.degree. C. (2 Torr)-67.1.degree. C. (<2 Torr), 22.8 g, 54
wt % (NMR) NBMeOAc, 13 wt % pyridine, 33 wt % acetic anhydride
[0079] II: 68.4-61.0.degree. C. (<2 Tarr), 501.5 g, 99.7%
exo-NBMeOAc [0080] III: 59.4-60.4.degree. C. (<2 Torr), 19.8 g,
99.5% exo-NBMeOAc. NMR showed an extra signal at 3.05 ppm.
[0081] Yield was 501.5 g (75% of theoretical). GC retention time:
4.51 minutes, exo-NBMeOAc.
Preparation of Endo-Norbornenemethyl Acetate (endo-NBMeOAc)
[0082] A 3-Liter glass flask, fitted with mechanical stirrer,
nitrogen inlet, addition funnel, and thermowell, was dried with a
hot air gun to 108.degree. C. under a nitrogen flush. After cooling
to room temperature, endo-norbornenemethanol (125.0 g, 1.0 mol) was
placed in the flask, followed by 4 Liters dry dichloromethane, 247
g (3.1 mol) dry pyridine, and another 500 ml dry dichloromethane.
Dimethylaminopyridine (0.5 g, 4.2 mmol) was added. Acetic anhydride
was added rapidly dropwise within 18 minutes, causing the reaction
temperature to rise from 24.degree. C. to 38.7.degree. C. After 34
minutes, GC analysis indicated only 1.8% starting material
remained. After 2 hours, no significant quantities of starting
material remained. The reaction mixture was allowed to stir
overnight at room temperature. GC analysis showed no further change
in product composition. The reaction was rotary evaporated to
remove dichloromethane and then rotary evaporated at 60.degree. C.
to remove excess pyridine and acetic anhydride. NMR analysis
indicated that the residue, totaling 165.6 g, still contained 4.3
wt % pyridine. The material was washed with 250 ml distilled water,
causing the lower organic phase to become very milky.
Dichloromethane (100 ml) was added to the aqueous phase, mixed, and
the phases separated. The organic phases were combined and washed
with 10% aqueous sulfuric acid. This caused the organic phase to
clear. A wash with 250 ml brine caused a phase reversal, leaving
the organic phase on top. The organic phase was washed with
3.times.250 ml brine to a final wash pH of 6. The organic phases
were dried over sodium sulfate, filtered, and rotary evaporated to
give 156.5 g. NMR and GC analysis showed no pyridine remained. The
product was vacuum distilled giving four fractions: [0083] I.
28.6.degree. C. (6 Torr)-58.8.degree. C. (1.95 Torr), 5.8 g, 98.4%
endo-NBMeOAc (GC) [0084] II. 55.2.degree. C. (1.90
Torr)-49.2.degree. C. (1.50 Torr), 125.2 g, 100% endo-NBMeOAc
[0085] III. 48.9.degree. C. (1.50 Torr)-50.6.degree. C. (1.50
Torr), 8.9 g, 100% endo-NBMeOAc [0086] IV. 51.degree. C. (1.50
Torr), 0.8 g, 100% endo-NBMeOAc
[0087] Total product was 140.7 g for 84% yield. GC retention time:
3.75 minutes, endo-NBMeOAc.
Preparation of Endo-Norbornenemethylmethanesulfonate
(Endo-NBMeOMs)
[0088] Endo-5-(2-hydroxymethyl)norbornene (104.79 g, 0.85 mol), 485
ml dichloromethane, and methanesulfonyl chloride (100.99 g, 0.88
mol) were placed in a 4-neck 3-L flask fitted with mechanical
stirrer, thermowell, nitrogen inlet, and addition funnel. 240 ml
dichloromethane was added to rinse in the methanesulfonyl chloride.
The stirred mixture was chilled to -11.1.degree. C. Triethylamine
(101.26 g, 1.00 mol) was added rapidly dropwise over a 2 hr period
with the temperature ranging from -11.1 to +7.0.degree. C. The
resulting yellow slurry was allowed to warm to 18.9.degree. C.
during 78 minutes. GC analysis indicated 0.3% unreacted starting
material remaining. An additional 3.82 g of methanesulfonyl
chloride was added and the mixture allowed to stir overnight at
room temperature. GC analysis indicated that 0.1% starting material
remained. Five hundred ml water was added to clear the solution.
The phases were separated. The dichloromethane portion was washed
with 450 ml of 1 N HCl and then washed with 4.times.1000 ml brine
to a wash pH=6. The dichloromethane solution was dried over sodium
sulfate, filtered, and rotary evaporated to 185.15 g liquid
(>100% yield). GC analysis gave mesylate content at 98.1%. NMR
analysis indicated 7.5 wt % dichloromethane remaining. Endo/exo
ratio was 99.1:0.9.
Preparation of Endo-5-(2-Iodomethyl)norbornene (Endo-NBMeI)
[0089] Endo-Norbornenemethylmethanesulfonate (185.15 g, 92.5%, 0.85
mol) and 1500 ml 2-pentanone were placed in a 4-neck 5-L flask
fitted with mechanical stirrer, condenser with nitrogen inlet
adapter, stopper, and thermowell. The mixture was mixed well before
adding 190.4 g (1.27 mol) sodium iodide and 200 ml 2-pentanone. The
mixture was heated to reflux. After 1.5 hrs reflux, the mixture
became very thick and was diluted with an additional 500 ml
2-pentanone. After another 1.5 hrs at reflux, another 500 ml of
2-pentanone was added. The mixture continued to thickened and began
to splash solids over the upper portions of the reaction flask. An
additional 250 ml 2-pentanone were added and the reaction cooled
from 100.9.degree. C. to 95-96.degree. C. to permit smoother
stirring. The reaction was allowed to continue overnight at
95-96.degree. C., then heated to 100.4.degree. C. for 2 hrs when GC
analysis indicated no starting material remained. Total reaction
time at >90.degree. C. was 25 hrs. The reaction was allowed to
stir and cool to 30.degree. C. Water (500 ml) was added to clear
the solution. The phases were separated. The aqueous phase was
extracted with 500 ml and 250 ml of ethyl acetate. The ethyl
acetate extracts were combined with 2-pentanone phase and rotary
evaporated at <35.degree. C. to give 226.7 g red oil. This was
diluted with 300 ml dichloromethane and washed with 2.times.200 ml
10% aqueous sodium bisulfite. The organic phase was then washed
with 300 ml brine, 300 ml saturated sodium bicarbonate, and 350 ml
brine to final wash pH=7. The dichloromethane solution was dried
over sodium sulfate, filtered, and rotary evaporated to 203.6 g.
Water (15 ml) was added and the mixture rotary evaporated until the
residual pentanone was removed and only water began to distill
over. The residue was dried over sodium sulfate, filtered, and
rinsed with dichloromethane. This was vacuum distilled through a
12-inch Vigreux column, giving:
[0090] 1. 42.1-50.3.degree. C. (1.35-1.40 Torr), 21.88 g, 88.3%
endo-NBMeI
[0091] 2. 46.5.degree. C. (1.25 Torr)-42.5.degree. C. (1.20 Torr),
58.37 g, 99.0% endo-NBMeI
[0092] 3. 43.3-39.7.degree. C. (1.15-1.20 Torr), 79.19 g, 99.5%
endo-NBMeI
[0093] 4. 40.0-34.9.degree. C. (1.15 Torr), 1.53 g, 98.3%
exo-NBMeI.
[0094] Yield of >99.0% endo-NBMeI was 137.56 g (69%).
Preparation of
Exo-.alpha.,.alpha.-bis(trifluoromethyl)bicyclo[2.2.1]hept-5-ene-2-ethano-
l (Exo-HFANB)
[0095] A 12-L 4-neck flask fitted with mechanical stirrer, dry ice
condenser, thermowell, and nitrogen inlet valve was heated and hot
air-dried to 110.degree. C. under a nitrogen flush. After cooling
to 32.degree. C., zinc dust (Alfa Aesar A13633, 222.52 g, 3.45 mol)
and then 2000 ml DrySolve dimethylacetamide was placed in the
flask. Next, Iodine (59.33 g, 0.23 mol) was placed in the flask,
followed by a rinse with 300 ml DrySolve dimethylacetamide. Within
7 minutes, the initially formed reddish color changed to green and
then to gray as the mixture warmed to 33.3.degree. C. NBMeI (539.54
g, 2.3 mol) was added all at once. The mixture was heated to
79.degree. C., when the reaction initiates an exotherm, causing the
temperature to rise to 115.degree. C. The heat source is removed
and the reaction allowed to cool back to 89.degree. C. Heating is
resumed. After one hour at >79.degree. C., GC analysis shows no
starting material remaining. The reaction is cooled to
-26.6.degree. C. with an acetonitrile/dry ice cooling bath. HFA
(466.1 g, 2.77 mol) was condensed into the reaction mixture. The
initial addition of HFA caused a temperature rise from -28 to
-19.1.degree. C. The cooling bath was drained and replaced with a
wet isopropanol/dry ice cooling bath. The reaction mixture was
stirred at -18.5 to -1.7.degree. C. for 5.3 hours. The mixture was
chilled back to -28.degree. C. before adding distilled water
carefully in 200 to 500 ml increments up to a total water volume of
3000 ml. An additional 1000 ml of water was added. The entire
mixture was poured into 4000 ml water. The zinc residues in the
reaction flask were treated with 1600 ml 3.5 N HCl and the
resulting mixture combined with the previous aqueous quench. The
reaction flask was rinsed further with .about.3.5 L water. The
combined aqueous quenches were extracted with 3.times.4000 ml
cyclohexane. The cyclohexane extracts were combined and washed with
1 gal brine to pH 7. After storing overnight under nitrogen, the
cyclohexane solution was extracted with 3.times.500 ml 25% aqueous
tetramethylammonium hydroxide (TMAOH). The combined TMAOH extracts
were washed with 3.times.1000 ml cyclohexane and then acidified
with 400 ml concentrated HCl. The lower phase was separated to
collect 657.09 g of crude HFANB. NMR analysis showed this contained
10.5 wt % dimethylacetamide (DMA).
[0096] The crude product was washed with 200 ml 31.5% aqueous
sulfuric acid. No phase separation resulted so the mixture was
diluted 1000 ml dichloromethane to force a slow phase separation.
The organic phase was washed with 2.times.200 ml 31.5% sulfuric
acid and then with 2.times.400 ml 31.5% sulfuric acid until NMR
analysis showed <0.3 wt % DMA remaining. The product solution
was washed with 500 ml brine, 500 ml saturated sodium bicarbonate,
2.times.500 ml brine, and with 500 ml brine containing 10 ml 3.5 N
HCl until the final wash pH=7. The product solution was dried over
sodium sulfate, filtered, and rotary evaporated. The residue was
distilled through a 14-inch Vigreux column. The following fractions
were collected: [0097] I. 42.6-49.5.degree. C. (2 Ton), 44.03 g,
99.2% (GC) [0098] II. 45.6-44.8.degree. C. (1.95 Torr), 168.83 g,
98.8% (GC) [0099] III. 41.5-43.9.degree. C. (1.90 Torr), 127.44 g,
99% (GC) [0100] IV. 41.5-43.2.degree. C. (1.85 Ton), 118.64 g,
99.3% (GC) [0101] V. 40.2-45.0.degree. C. (1.75-1.80 Torr), 14.65
g, 99.1% (GC), contains 0.4 wt % DMA (NMR) [0102] VI.
44.9-49.9.degree. C. (1.80 Torr), 3.10 g, 99.1% (GC), contains 0.8
wt % DMA (NMR) [0103] VII. 51.8-63.3.degree. C. (1.80 Torr), 7.55
g, 98.65% (GC), contains 4.4 wt % DMA (NMR)
[0104] High purity exo-HFANB (>99%), combined fractions I-IV,
was 458.94 g for 73% yield.
Preparation of
Endo-.alpha.,.alpha.-bis(trifluoromethyl)bicyclo[2.2.1]hept-5-ene-2-ethan-
ol (Endo-HFANB).
[0105] A 3-L 3-neck flask fitted with mechanical stirrer, dry ice
condenser, thermowell, and nitrogen inlet was heated and hot
air-dried to -105.degree. C. under a nitrogen flush. After cooling
to room temperature, zinc dust (Alfa-Aesar A13633, 57.70 g, 0.88
mol) was placed in the flask, followed by 500 ml DriSolve
dimethylacetamide (DMA). The mixture was stirred as iodine (15.0 g,
0.059 mol) was added, followed by 100 ml dimethylacetamide rinse.
The mixture fumes, warms to 32.3.degree. C. and became green. After
3 minutes, the zinc slurry had turned back to blue-gray. After
waiting an additional nine minutes, endo-NBMeI (137.56 g, 0.59 mol)
was added all at once. The mixture was heated to 80.degree. C. Upon
reaching 80.degree. C., the temperature suddenly climbed to
96.degree. C. before subsiding after the heating source had been
removed. The heating source was replaced after the temperature
dropped to 86.degree. C. After 1 hour, GC analysis showed no NBMeI
remaining. The mixture was stirred an additional 30 min at
>80.degree. C. before cooling to -29.8.degree. C. in an
acetonitrile/dry ice cooling bath. Hexafluoroacetone (HFA) (120.5
g, 0.73 mol) was condensed into the reaction mixture. The
temperature ranged from -30.7 to -23.4.degree. C. during the 17
minute addition time. The cooling bath was replaced with a
methanol/ice cooling bath. The reaction mixture was stirred at
-27.9 to -1.2.degree. C. for 4.25 hours when GC analysis indicated
that the endo-methylnorbornene (NBMe) (from hydrolyzed NBMeZnI) to
HFANB signal ratio had become constant. The mixture was chilled to
-30.9.degree. C. before adding deionized water carefully in 50,
100, and 250 ml increments up to a total water volume of 1500 ml.
Maximum temperature reached was -2.2.degree. C. The liquid was
decanted from the zinc salts. 500 ml water and 450 ml 3.5N HCl was
added to the zinc salts, thoroughly mixed, and then combined with
the earlier decant. The combined aqueous mixture was extracted with
3.times.1000 ml cyclohexane. The cyclohexane extracts were washed
with 1000 ml brine to pH 5. GC analysis showed 61.3% HFANB in the
extracts.
[0106] The cyclohexane extracts were extracted with 210 ml 25%
aqueous tetraammonium hydroxide (TMAOH). GC analysis indicated that
5.9% HFANB remained in the cyclohexane phase, so the cyclohexane
solution was extracted with an additional 50 ml 25% TMAOH. This
left only 1.8% HFANB in the cyclohexane phase. The TMAOH extracts
were combined and washed with 3.times.500 ml cyclohexane. The
aqueous phase was acidified with 100 ml concentrated HCl to pH 1. A
lower phase totaling 117.15 g of 90.1% purity HFANB separated out.
GC analysis also indicated 6.1% dimethylacetamide (DMA) adduct
impurity. The crude HFANB was diluted with 250 ml dichloromethane
and then washed with 2.times.100 ml 10% sulfuric acid, but GC
analysis showed this was ineffective for removing the DMA adduct.
The crude product was washed with 2.times.100 ml and 200 ml 31.5%
sulfuric acid. GC analysis show no DMA adduct remained. The
dichloromethane solution was washed with 4.times.500 ml brine to pH
5. The product solution was dried over sodium sulfate, filtered,
and rotary evaporated to 92 g liquid with 96.9% purity. This was
vacuum distilled through a 12-inch Vigreux column. The following
fractions were collected: [0107] I. 31.7-43.1.degree. C. (1.55-1.95
Torr), 10.74 g, 99.3% endo (GC) [0108] II. 39.5-35.6.degree. C.
(1.15-1.50 Torr), 25.82 g, 99.7% endo(GC) [0109] III.
33.9-30.1.degree. C. (1.20-1.10 Ton), 36.02 g, 99.7% endo(GC)
[0110] IV. 32.3-26.5.degree. C. (0.87-0.89 Torr), 4.21 g, 99.1%
endo(GC), 0.3% DMA adduct
[0111] Total HFANB at >99% purity was 76.79 g for 48% yield.
Fractions I, II, and III showed a prominent -70.7 ppm signal in the
19F NMR. These fractions were combined, diluted with 100 ml
cyclohexane, and extracted with 2.times.100 ml 25% TMAOH. The TMAOH
extracts were washed with 3.times.100 ml cyclohexane and then
acidified with 50 ml concentrated HCl to pH<2. The product
separated as the lower phase. This was removed, washed with
2.times.200 ml brine to pH 6, dried over sodium sulfate, filtered
and rotary evaporated to 69.54 g. NMR. analysis indicated <0.4%
of the component giving the -70.7 ppm signal in the .sup.19F NMR.
This material was vacuum distilled through a 12-inch Vigreux column
to give the following fractions:
[0112] B1 27.2-41.2.degree. C. (4.50-4.75 Torr), 40 mg forerun
[0113] B2. 45.1-39.0.degree. C. (2.25-3.00 Torr), 1.11 g, 99.5%
endo(GC)
[0114] B3. 37.6-31.5.degree. C. (1.05-1.20 Torr), 42.62 g, 99.6%
endo(GC)
[0115] B4. 30.5-27.9.degree. C. (0.82-1.05 Torr), 21.87 g, 99.6%
endo(GC).
[0116] 19F NMR analysis showed little or no -70.7 ppm signal in
fractions B3 and B4. Fractions B3 and B4 totaled 64.49 g for 40%
yield. GC Retention time: 4.55 min (endo-HFANB), 4.43 min
(exo-HFANB), 2.09 min.(endo-NBMe), 2.66 min (DMA adduct).
Preparation of Exo-Norbornenecarboxylic Acid (exo-NBCO.sub.2H) (via
AgNO.sub.3 and NaOH)
[0117] Exo-NBCHO (1188 g of 49.2 wt % in toluene, .about.4.79 mol)
was placed in a 50-Liter glass flask fitted with mechanical
stirrer, thermowell, stopper, and 2-Liter addition funnel. The
aldehyde was diluted with 10 L reagent alcohol and chilled to
-13.7.degree. C. Silver nitrate (1226 g, 7.2 mol, 1.5 equivalents)
was dissolved in 1800 ml water and added in portions to the
aldehyde solution. Addition was complete in 12 minutes while the
temperature ranged from -13.7 to -0.9.degree. C. The reaction
mixture was cooled to -11.6.degree. C. before adding sodium
hydroxide (575 g, 14.4 mol) in 10 L of water. The addition was
completed in four hours while the temperature ranged from -11.6 to
-0.2.degree. C. The mixture was stirred another hour at -3.degree.
C. until GC analysis indicated no further increase in product
formation. The reaction mixture was filtered to remove the silver
residue and the resulting clear, nearly colorless filtrate was
acidified with 1400 ml concentrated hydrochloric acid to pH 1. The
mixture was extracted with 3.times.4000 ml dichloromethane. The
combined extracts were washed with 2 gallons brine and then
2.times.1 gallon brine until the wash pH=5. The extracts were
rotary evaporated to 690 g of an oil. This was dissolved in 2000 ml
dichloromethane and then extracted with 2 Liters 8% aqueous sodium
hydroxide. The aqueous sodium hydroxide extract was washed with
4.times.600 ml dichloromethane until GC analysis showed no
exo-NBMeOH byproduct in the last wash.
[0118] The aqueous sodium hydroxide extract was acidified with 310
ml concentrated hydrochloric acid. The resulting phases were
separated. The upper aqueous phase was extracted with 2.times.600
ml dichloromethane. The organic phases were combined and washed
with 1000 ml brine. This resulted in a slow-separating milky
emulsion. An additional 500 ml dichloromethane and 500 ml water
were added to break the emulsion and affect phase separation. The
organic portions were dried over sodium sulfate, filtered, and
rotary evaporated to 533.8 g, showing 100% purity by GC. NMR
analysis in deuteriomethanol solvent shows only 1.3%
endo-isomer.
[0119] The final brine wash was acidified with 50 ml concentrated
hydrochloric acid to pH 1. This was extracted with 3.times.600 ml
dichloromethane. The extracts were washed with 500 ml brine to pH
5, then dried over sodium sulfate, filtered, and rotary evaporated
to give 50.4 g, 100% purity exo-NBCO.sub.2H by GC. Total, yield was
584.4 g (.about.88% yield, 72% yield from NBCN). NMR. analysis
indicated the isolated product still contained 6-7%
dichloromethane. GC retention time: 5.50 minutes.
Preparation of Endo-NBCO.sub.2H (Via AgNO.sub.3 and NaOH)
[0120] Endo-NBCHO (948 g of 56.7 wt % in toluene, .about.4.4 mol)
was placed in a 50-Liter glass flask fitted with mechanical
stirrer, thermowell, stopper, and 2-Liter addition funnel. The
aldehyde was diluted with 9200 ml reagent alcohol and chilled to
-11.4.degree. C. Silver nitrate (1128 g, 6.6 mol, 1.5 equivalents)
was dissolved in 1700 ml water and added in portions to the
aldehyde solution. Addition was complete in 19 minutes while the
temperature ranged from -11.4 to -0.5.degree. C. The reaction
mixture was cooled to -8.0.degree. C. before adding sodium
hydroxide (529 g, 13.2 mol) in 9.2 Liters of water. The addition
was completed in 5 hours 54 minutes while the temperature ranged
from -8.0 to -0.2.degree. C. The mixture was stirred another 1.5
hours at <0.degree. C. until GC analysis indicated no further
increase in product formation. The reaction mixture was filtered to
remove the silver residue, the silver residue washed with reagent
alcohol, and the resulting clear, nearly colorless filtrate was
acidified with 1200 ml concentrated hydrochloric acid to pH 1. The
mixture was extracted with 3.times.4000 ml dichloromethane. The
combined extracts were washed with 3.times.2 gallons brine until
the wash pH=5. The extracts were rotary evaporated to yield 738 g
of an oil. This was dissolved in 2000 ml dichloromethane and then
extracted with 2 Liters 8% aqueous sodium hydroxide. The aqueous
sodium hydroxide extract was washed with 4.times.1000 ml
dichloromethane until GC analysis showed no endo-NBMeOH byproduct
in the last wash.
[0121] The aqueous sodium hydroxide extract was acidified with 335
ml concentrated hydrochloric acid to pH 2. The resulting phases
were separated. The upper aqueous phase was extracted with
2.times.500 ml dichloromethane. The organic phases were combined
and washed with 1000 ml brine to pH 4. The organic portions were
dried over sodium sulfate, filtered, and rotary evaporated to 579.3
g (95% yield, 71% yield from endo-NBCN), showing 99.8% purity
endo-NBCO.sub.2H by GC. The material crystallized overnight, losing
significant mass by evaporation of residual dichloromethane. NMR
analysis reveals <5.6% exo-isomer and 1.8 wt % dichloromethane.
Final yield was 478.1 g (78.7% yield from endo-NBCHO, 51% yield
from endo-NBCN). GC retention time: 5.46 minutes,
endo-NBCO.sub.2H.
[0122] A dichloromethane extract of an aliquot from the initial
brine wash revealed via NMR analysis that potentially up to 34 g of
ethyl ester May have be present.
Preparation of Exo NBCO.sub.2H (via NaClO.sub.2)
[0123] Exo-NBCHO (87.5:12.5 exo:endo, 1.2 g, 0.01 mol) was
dissolved in 50 ml melted t-BuOH. 2-Methyl-2-butene (22 ml, 0.2
mol) was added to the aldehyde solution. NaClO.sub.2 (80%, 1.7 g,
0.02 mol) was dissolved in 10 ml deionized water. Sodium dihydrogen
phosphate (3.00 g, 0.03 mol) was added to the NaClO.sub.2 solution
and then sonicated to dissolve, giving an aqueous solution with pH
between 4-5. The aldehyde solution was cooled to 17.5.degree. C.
before adding the oxidant solution dropwise. The reaction solution
became intensely yellow while cooling to 11.1.degree. C. Addition
was complete in 8 minutes. GC analysis showed little aldehyde
remaining, while the acid product gave an exo/endo ratio of 92:8.
The reaction became colorless after stirring 66 minutes at
17.9.degree. C. GC analysis showed no further increase in product
formation as the % acid maximized at 89%. The solvents were removed
by rotary evaporation and the residue taken up in 10 ml deionized
water. The solution was made basic to pH 11 with 12.5 ml 8% aqueous
NaOH. This was washed with 2.times.20 ml dichloromethane and then
re-acidified to pH 3 with 7.5 ml 3.5N aqueous HCl. The acidified
solution was extracted with 3.times.20 ml dichloromethane. The
dichloromethane extracts were washed with 25 ml brine to pH 5, then
dried over sodium sulfate, filtered, and rotary evaporated to give
0.74 g colorless liquid (54% yield). GC analysis shows 97.7% purity
with exo/endo ratio of 90:10. NMR analysis indicates 10-15%
endo-isomer present, but shows "noise" in the aliphatic region
between 2-3.2 ppm. GC retention times: 5.08 min (exo-NBCO.sub.2H),
5.15 min (endo-NBCO.sub.2H).
Preparation of Endo NBCO.sub.2(Via Oxone.RTM.)
[0124] A 250 mL round bottom, 3-necked flask was equipped with a
magnetic stir bar, condenser, stopper, and septum. To the flask was
added endo-NBCN (5.96 g, 50 mmol), and the contents were cooled to
0 to 5.degree. C. via an ice-bath. In a continuously purged
nitrogen environment, 1.0 M DIBAL-H in hexanes (50 mL, 50 mmols)
was added dropwise while stirring. After the addition was complete,
the reaction was allowed to stir for 15 minutes at 0 to 5.degree.
C. The contents were transferred to a separatory funnel containing
cold, dilute HCl (1N, 100 mL). The resulting aldehyde was extracted
with cold diethyl ether (4.times.100 mL) and charged to a flask
containing a slurry of DMF (73 mL) and solid, oxidizing agent
Oxone.RTM. (DuPont CAS-RN 70693-62-8) (2
KHSO.sub.5.KHSO.sub.4.K.sub.2SO.sub.4) (30.6 g). The mixture was
stirred at 0 to 5.degree. C. in an open atmosphere where the
aldehyde was oxidized to the corresponding carboxylic acid. The
contents were transferred to a separatory funnel where dilute HCl
was added to dissolve any residual Oxone.RTM.. The aqueous layer
was discarded and the organic layer was washed with water
(4.times.100 mL) to remove DMF. The organic layer was extracted
with aqueous potassium carbonate (25 wt %), and the aqueous layer
was acidified with concentrated HCl. The resulting precipitate was
extracted with diethyl ether (3.times.100 mL), dried over
MgSO.sub.4, and filtered. The diethyl ether was removed under
reduced pressure to afford pure endo-NBCO.sub.2H (5.81 g,
84.1%).
Preparation of Exo-Norbornenemethoxymethyl Hexafluoropropanol
(Exo-NBMMHFP)
[0125] NaH (60%, 175.6 g, 4.39 mol) was placed in 4-neck 12-L flask
fitted with mechanical stirrer, addition funnel, nitrogen gas
inlet, and thermowell. The reaction apparatus had been dried
earlier by heating with a hot air drier to 120.degree. C. under a
nitrogen flush. Dry THF (1700 ml) was added and the resulting
slurry mechanically stirred while cooling to -11.2.degree. C.
Exo-NBCH.sub.2OH (448 g, 3.61 mol, fractions 4 & 5) was
dissolved in 420 ml dry THF and added dropwise to the NaH/THF
mixture. Addition time was 25 minutes with the temperature ranging
from -12.2.degree. C. to -8.9.degree. C. The reaction was allowed
to warm to room temperature (17.degree. C.) and stir overnight. The
reaction was cooled to -18.2.degree. C. and 657.2 g (3.65 mol)
hexafluoroisobutylene epoxide (HFIBO) was added dropwise. Addition
time was 2 hrs with the temperature ranging from -18.4.degree. C.
to -0.1.degree. C. GC analysis showed 20.8% unreacted starting
material. The mixture was allowed to warm to room temperature
(18.7-27.7.degree. C.) and stir another five hours. GC analysis
detected no unreacted starting material. The mixture was cooled to
-11.3.degree. C. and 1750 ml water was added to quench. The quench
time was 81 minutes and quenching temperature reached a maximum of
-2.0.degree. C. Then, 375 ml concentrated hydrochloric acid was
added, bringing the pH to 2. The deep yellow THF layer was
separated from the lower aqueous phase. The aqueous phase was
extracted with 2.times.500 ml MTBE. The organic portions were
combined and then split into two 2-L portions. Each was washed with
2.times.1000 ml brine to pH 5.
[0126] The 2nd organic portion gave an emulsion so was diluted
further with 3.times.250 ml MTBE to hasten separation. The combined
organic portions were dried over sodium sulfate overnight,
filtered, and rotary evaporated to give 1279.8 g of an amber
liquid. GC analysis indicated 98.6% purity. The crude product was
vacuum distilled through a 12-inch Vigreux column: [0127] 1.
22.50.degree. C. (1.65 Torr)--91.8.degree. C. (1.15 Torr), 33.38 g,
95.3% (GC), contains THF [0128] 2. 89.20.degree. C. (0.98
Torr)--76.20.degree. C. (0.89 Torr), 121.08 g, 98.3% (GC), NMR ok
[0129] 3. 75.0.degree. C. (0.84 Torr)--64.9.degree. C. (1.00 Torr),
257.99 g, 98.8% (GC), NMR ok [0130] 4. 64.4.degree. C. (0.86
Torr)--62.2.degree. C. (0.95 Torr), 637.58 g, 99.7% (GC), NMR ok
[0131] 5. 61.4.degree. C. (0.91 Torr)--63.0.degree. C. (0.94 Torr),
19.32 g, 98.1% (GC), extra signals in NMR.sup.-. [0132] 6.
53.8.degree. C. (0.91 Torr)--124.1.degree. C. (0.98 Torr), 4.63 g,
yellow [0133] 7. 120.2-140.1.degree. C. (0.96 Torr), 5.70 g, yellow
Pot, 63.5 g
[0134] Fractions 2, 3, and 4 were combined to give 1016.65 g (93%
yield) with 99.2% (GC) purity. Retention time: 4.902 min.
Preparation of Endo-NBMMHFP
[0135] NaH (60%, 17.73 g, 0.44 mol) was placed in 500-ml flask
fitted with mechanical stirrer, addition funnel, nitrogen gas
inlet, and thermowell. The reaction apparatus had been dried
earlier with a hot air drier to .about.120.degree. C. under a
nitrogen flush. Dry THF (200 ml) was added and the resulting slurry
mechanically stirred while cooling to -16.8.degree. C.
Endo-NBCH.sub.2OH (50.0 g, 0.403 mol) was dissolved in 50 ml dry
THF and added dropwise to the NaH/THF mixture. Addition time was 32
minutes with the temperature ranging from -16.8.degree. C. to
-0.8.degree. C. The white slurry was allowed to warm to room
temperature and stir overnight. The reaction was cooled to
-17.4.degree. C. and 72.8 g (0.40 mol) hexafluoroisobutylene
epoxide (HFIBO) was added dropwise. Addition time was 26 min with
the temperature ranging from -15.1.degree. C. to -2.4.degree. C.
The cooling bath was removed and the reaction very quickly warmed
to 11.3.degree. C., where it was cooled briefly again to slow the
exotherm. The reaction was stirred 4.5 hours at 15-18.degree. C.
until GC analysis showed no further change. The mixture was cooled
to -8.degree. C. and 200 ml water was added to quench. The
quenching temperature reached a maximum of +0.2.degree. C. Then, 40
ml of concentrated hydrochloric acid was added. The golden THF
layer was separated from the lower aqueous phase. The aqueous phase
was extracted with 2.times.100 ml MTBE. The organic portions were
combined and washed with 3.times.100 ml brine, then 4.times.200 ml
brine to pH 6. The extracts were dried over sodium sulfate,
filtered, and rotary evaporated to give 129.06 g of an oil. GC
analysis indicated 93.9% purity and 4.4% unreacted endo-alcohol.
The material was distilled in the Kugelrohr oven, giving 87.03 g at
110.degree. C. (2 ton) with 98.5% purity and 1.5% endo-NBMeOH. An
additional 1.67 g was collected at 120-130.degree. C. (2 torr) with
98.9% purity and 1.1% endo-NBMeOH. The 87-g sample was redistilled
in the Kugelrohr oven to give 50.80 g at 104.degree. C. (1 ton)
with 99.2% purity and contained 0.8% endo-NBMeOH. A forerun of
28.18 g was also collected at 104.degree. C. (1 torr), giving 96.6%
purity and 3.4% endo-NBMeOH. Yield of >99% purity product was
41%. Yield of adduct with >98% purity was 72%. GC retention
times were 5.29 minutes (endo-NBMMHFP), 3.13 min (endo-NBMeOH).
Exo-Norbornenylmethoxydiphenylmethylsilane
(Exo-NBCH.sub.2OSiMePh.sub.2)
[0136] A charge of exo-norbornenyl methanol (96 grams, 0.77 mol)
was added in a five-necked, 500 mL glass jacketed reactor, which
was sparged with nitrogen. The reactor was heated via a
heating/cooling circulating water bath with a 75.degree. C. set
point. At an internal reactor temperature of 75.degree. C.,
diphenylmethyl(dimethylamino silane (171 grams, 0.71 mol) was added
drop wise through an addition funnel to prevent an exothermic
reaction from occurring. Next, the internal reactor temperature was
heated to 100.degree. C. It was held for up to 24 hours and sampled
with GC monitoring to ensure the dimethylamine content was less
than 1% in the reactor. The reactor was connected to an acid base
scrubber, which neutralized the dimethylamine. The reaction mixture
was cooled and collected into a bottle. The crude material of
exo-norbornenylmethoxydiphenylmethylsilane (209 grams, 71% yield)
was purified through a short path head distillation setup at
150.degree. C. and 60 mTorr to yield 140 grams (>98%, 100% exo
content) as a colorless liquids. Proton NMR indicated only the
presence of exo-NBCH.sub.2OSiMePH.sub.2, indicating that the
diastereomeric purity of the starting material was maintained.
Exo-Norbornenyl Ethoxy Diphenylmethyl Silane
(Exo-NBCH.sub.2CH.sub.2OSiMePh.sub.2
[0137] A charge of exo-norbornenylethanol
(exo-NBCH.sub.2CH.sub.2OH) (246 grams, 1.78 mol) was added in a
five-necked, 500 mL glass jacketed reactor, which was sparged with
nitrogen. The reactor was heated via a heating/cooling circulating
water bath with a 75.degree. C. set point. At an internal reactor
temperature of 75.degree. C., diphenylmethyl (dimethylamino)silane
(390 grams, 1.62 mol) was added drop wise through an addition
funnel to prevent an exothermic reaction from occurring. Next, the
internal reactor temperature was heated to 100.degree. C. It was
held for 24 hours and sampled with GC monitoring to ensure all the
dimethylamine gas was less than 1% in the reactor. The reactor was
connected to an acid base scrubber, which neutralized the
dimethylamine being evolved. The reaction mixture was cooled and
collected into a bottle. The crude material of
exo-norbornenylethoxydiphenylmethylsilane (540 grams, 78% yield)
was purified through a short path head distillation setup at
160.degree. C. and 50 mTorr to yield 317 grams (>98% purity) as
a colorless liquid. Proton NMR indicated
exo-NBCH.sub.2CH.sub.2CH.sub.2OSiMePh.sub.2 product possessed the
same diastereomeric purity as the starting
exo-NBCH.sub.2CH.sub.2OH.
Synthesis of Endo-Norbornene-carboxylic Acid
Tetrahydro-2-oxo-3-furanyl Ester (Endo-GBLNB)
[0138] An appropriately sized flask was charged with
.alpha.-Br-.delta.-butyolactone (26.1 g, 158 mmols). After
equipping the flask with a thermometer, septum, and condenser,
endo-NBCO.sub.2H (20.0 g, 145 mmols) and tetrahydrofuran (100 mL)
was added. Under a nitrogen sweep, the solution was booled to
.about.5.degree. C. with the aid of an ice-bath. Next,
triethylamine (19.1 g, 189 mmols) was injected through the septum
and the contents were allowed to warm to ambient temperature after
which reflux for 20 h. After allowing to cool to ambient
temperature, the contents were filtered to separate byproduct. To
the filtrate was diluted with methylene chloride, and the solution
was extracted with 5% sodium bicarbonate (2.times.50 mL) and water
(1.times.50 mL). The solution was dried over magnesium sulfate and
filtered. Diethyl ether was added to the solution to aid in
recrystallization. Endo-GBLNB was collected by filtration (21.5 g,
67% yield). Proton NMR indicated endo-GBLNB product possessed the
same diastereomeric purity as the starting endo-NBCO.sub.2H.
Synthesis of Exo-GBLNB
[0139] An appropriately sized flask was charged with
.alpha.-Br-.delta.-butyolactone (26.3 g, 160 mmols). After
equipping the flask with a thermometer, septum, and condenser,
endo-NBCO2H (20.0 g, 145 mmols) and tetrahydrofuran (100 mL) was
added. Under a nitrogen sweep, the solution was cooled to
.about.5.degree. C. with the aid of an ice-bath. Next,
triethylamine (19.1 g, 189 mmols) was injected through the septum
and the contents were allowed to warm to ambient temperature after
which reflux for 20 h. After allowing to cool to ambient
temperature, the contents were filtered to separate byproduct. To
the filtrate was diluted with methylene chloride, and the solution
was extracted with 5% sodium bicarbonate (2.times.50 mL) and water
(1.times.50 mL). The solution was dried over magnesium sulfate and
filtered. Diethyl ether was added to the solution to aid in
recrystallization. Exo-GBLNB was collected by filtration. Proton
NMR indicated exo-GBLNB product possessed the same diastereomeric
purity as the starting exo-NBCO.sub.2H.
Synthesis of Endo-Norbornene-carboxylic Acid Ethylcyclohexyl Ester
(Endo-ECHENB)
[0140] Triethylamine (5.54 g, 54.8 mmols) and p-toluene sulfonyl
chloride (8.35 g, 43.8 mmols) were dissolved in dimethylacetamide
(2.29 g) in a sealed septum bottle. The solution was injected into
an appropriately sized bottle containing endo-NBCO.sub.2H (5.04 g,
36.5 mmols), 1-ethylcyclohexanol (5.62 g, 43.8 mmols), and
dimethylacetamide (2.00 g) heated to 50.degree. C. under nitrogen.
After heating for 20 h, the solution was precipitated into
tetrahydrofuran and filtered to remove triethylamine hydrogen
chloride. Toluene was added to the filtrate, and it was washed with
15% sodium hydroxide (2.times.30 mL), and water (2.times.50 mL).
Purification via column chromatography afforded endo-ECHENB. Proton
NMR indicated the product to be high purity endo-ECHENB.
Synthesis of Exo-ECHENB
[0141] Triethylamine (5.54 g, 54.7 mmols) and p-toluene sulfonyl
chloride (8.35 g, 43.8 mmols) were dissolved in dimethylacetamide
(2.29 g) in a sealed septum bottle. The solution was injected into
an appropriately sized bottle containing exo-NBCO2H (5.04 g, 36.5
mmols), 1-ethylcyclohexanol (5.62 g, 43.8 mmols), and
dimethylacetamide (2.00 g) heated to 50.degree. C. under nitrogen.
After heating for 20 h, the solution was precipitated into
tetrahydrofuran and filtered to remove triethylamine hydrogen
chloride. Toluene was added to the filtrate, and it was washed with
15% sodium hydroxide (2.times.30 mL), and water (2.times.50 mL).
Purification via column chromatography afforded exo-ECHENB. Proton
NMR indicated the product to be high purity endo-ECHENB.
Synthesis of Exo-/Endo-TMSETD
(tetracyclododecenylethyltrimethoxysilane) from
Exo-/Endo-TMSENB
[0142] A high-pressure microtube was charged with TMSENB (2.74 g,
11.3 mmols) and DCPD (0.26 g, 2.0 mmols). The microtube was heated
to 220.degree. C. for 4 h, and the contents were analyzed. GC
retention times: 9.740 (TMSENB, 69.3 area %), 10.973 (trimers, 1.58
area %), 14.919 (TMSETD, 16.8 area %), 15.466 (TMSETD, 8.4 area %).
Total TMSETD yield was 25.2% from GC area %.
Synthesis of Exo-/Endo-TMSETD from Exo-TMSENB
[0143] A high-pressure microtube was charged with exo-TMSENB (2.74
g, 11.3 mmols) and DCPD (0.26 g, 2.0 mmols). The microtube was
heated to 220.degree. C. for 4 h, and the contents were analyzed.
GC retention times: 9.763 (TMSENB, 54.9 area %), 10.974 (trimers,
1.52 area %), 14.808 (TMSETD, 2.03 area %), 15.625 (TMSETD, 38.4
area %). Total TMSETD yield was 40.43% from GC area %.
Synthesis of Exo-/Endo-TDCN
(octahydrodimethanonaphthalenecarbonitrile) from Exo-NBCN
[0144] A high-pressure microtube was charged with exo-NBCN (1.76 g,
14.8 mmols) and CPD (0.49 g, 7.4 mmols). The microtube was heated
to 220.degree. C. for 4 h, and the contents were analyzed. GC
retention times: 12.716 (TDCN, 5.7 area %), 13.005 (TDCN, 1.1 area
%), 13.386 (TDCN, 46.8 area %).
Polymerization Example--Preparation of BFANB/MeOAcNB.
[0145] Three polymerizations were performed. For each, a
diastereomeric mixture of HFANB (0.017 mmol) was charged to an
appropriately sized reaction vessel with 0.014 mmol of either
essentially pure endo-NBMeOAc (polymerization A), a diastereomeric
mixture of NBMeOAc (polymerization B), or essentially pure
exo-NBMeOAc (polymerization C). In addition to the aforementioned
monomers, the reaction vessels were each charged with
N-dimethylanilinium tetrakis (pentafluorophenyl)borate (DANFABA
0.090 mmol), ethyl acetate (2.5 g) and toluene (7.4 g). Then
(acac)palladium(II)bis(acetonitrile)tetrakis(pentafluorophenyl)borate]
(Pd-967 0.03 mmol) was added to each reaction vessel followed by
the addition of 3.26 mmol of formic acid. Each reaction vessel was
heated to 90.degree. C. and stirred for 18 hours. After cooling, a
total solids analysis was done to determine percent conversion
(using a total solids analyzer (Mettler Toledo HR73 halogen
moisture analyzer) and a GPC analysis was used to determine
molecular weight (gel permeation chromatography using
poly(styrene)standards). Next, each polymer was purified to remove
residual catalyst and then precipitated into hexane and dried in a
vacuum oven.
TABLE-US-00002 TABLE 2 Formic Acid (mol % on % Example Isomer
monomer) Conv. Mw Mw/Mn A endo/exo-HFA; 10 97 2373 1.34
endo-MeOAcNB B endo/exo-HFA; 10 100 2634 1.40 endo/exo- MeOAcNB C
endo/exo-HFA; 10 100 3387 1.49 exo-MeOAcNB
[0146] As seen in Table 2, the essentially pure exo- and
endo-NBMeOAc monomers are effectively polymerized. Further, it can
be seen that polymerization Example A results in the lowest
molecular weight and % conversion while polymerization Example C
has the highest molecular weight and polymerization Example B
exhibits an intermediate molecular weight. Thus, such
polymerization examples demonstrate the higher reactivity of the
exo-NBMeOAc as compared to both the diastereomeric mixture and the
endo-epimer. Still further, it should be apparent that having
essentially pure exo- and endo-isomers allows for polymerization
embodiments in accordance with the present invention to be directed
to making alternating polymers, block polymers and gradient
polymers where the specific configurations of such polymers are
based on the isomeric configuration of the specific repeating units
employed as well as different materials.
[0147] By now it should be realized that by and through the above
examples, data and discussion, embodiments in accordance with the
present invention have been demonstrated. For example, embodiments
that provide for the preparation of both endo- and exo-epimers of a
5-NBCHO have been shown as well as embodiments that demonstrate the
forming of both endo- and exo-epimers of a variety of other
norbornene-type monomers derived from such 5-NBCHO isomers.
Further, it has been taught that
bis-cyano[bis-carboxaldehyde]norbornenes and TD or higher homologs
of such carboxaldehydes can also be used to form a wide variety of
desirable norbornene-type monomers. Still further it has been
taught that a variety of homologation reactions can be employed to
increase the length of functional groups by inserting one or more
methylene groups therein.
[0148] Additionally, embodiments in accordance with the present
invention that are directed to the polymerization of essentially
pure monomeric epimers have been described and shown. Also
described are embodiments of the present invention that are
directed to polymerization of norbornene-type monomers where the
monomer feedstock for the polymerization encompasses a specific
ratio of endo- and exo-epimers of one or several monomer types. As
it will be understood, only by and through embodiments of the
present invention directed to preparing both the endo- and
exo-epimer of a variety of monomer types is it possible to
determine a desired ratio of such epimers for any one (or several)
monomer-type(s) and then create a monomer feedstock having this
(these) desired ratio(s) and to polymerize such a feedstock to
create a polymer that incorporates such epimers as repeating units.
Still further, it will be appreciated that such polymers having
such desired ratios are then tailored to have specific polymer
properties. For example a desired dissolution rate in an alkali
solution, molecular weight or a specific elongation to break or the
like. For example as shown in Table 2, where an HFANB/NBMeOAc
polymer having a Mw of about 2400 is desired, such can be obtained
by using an essentially pure endo-isomer of NBMeOAc while where a
Mw of about 3400 is needed, using the corresponding essentially
pure exo-isomer would be appropriate.
[0149] It should be appreciated that the synthetic yields of the TD
monomers made from high purity exo-norbornene analogs, shown above,
are indicative of the higher reactivity of such monomers when
compared to an analogous endo-monomer or a diastereomeric mixture
of such monomers. Thus the total yield of TMSETD made from
exo-/endo-TMSENB is only about 60% of the yield obtained when the
starting material was essentially pure exo-TMSENB. Still further,
it should be appreciated that in comparing the reactions of
analogous exo- and endo-isomers, the exo-isomer generally exhibits
higher reactivity and transformations of such an exo-isomer results
in shorter reaction times and higher yields than the
endo-isomer.
[0150] While the invention has been explained in relation to
descriptions of various embodiments and examples, it is to be
understood that modifications thereof will become apparent to those
skilled in the art upon reading this specification. Any such
modifications are therefore within the scope and spirit of the
embodiments of the present invention and shall be understood to
fall within the scope of the appended claims.
* * * * *