U.S. patent application number 11/985381 was filed with the patent office on 2008-05-15 for methods for preparing epoxides.
Invention is credited to Venkatram R. Mereddy, Kamlesh J. Padiya, P.V. Ramachandran.
Application Number | 20080114193 11/985381 |
Document ID | / |
Family ID | 38541921 |
Filed Date | 2008-05-15 |
United States Patent
Application |
20080114193 |
Kind Code |
A1 |
Ramachandran; P.V. ; et
al. |
May 15, 2008 |
Methods for preparing epoxides
Abstract
The invention includes methods for preparing halohydrins and
epoxides. A method of preparing halohydrins can include exposing
(R.sup.1CHXCH.sub.2O--).sub.2SO.sub.2 to R.sup.2COOH to produce
R.sup.2COOCH.sub.2CHXR.sup.1 and hydrolyzing the
R.sup.2COOCH.sub.2CHXR.sup.1 to produce the halohydrin
R.sup.1CHXCH.sub.2OH. R.sup.1 and R.sup.2 can be the same or
different single elements and/or organic groups and X can be a
halogen. A method of preparing an epoxide can include combining a
sulfuric acid containing solution with a halogen to produce a first
mixture and exposing the first mixture to trifluoropropene to
produce a second mixture. The second mixture can be combined with
acetic acid to produce an acetyl halohydrin of trifluoropropene and
the acetyl halohydrin can be hydrolyzed to form a halohydrin of
trifluoropropene. The halohydrin can be converted to a
trifluoropropyl epoxide.
Inventors: |
Ramachandran; P.V.; (West
Lafayette, IN) ; Padiya; Kamlesh J.; (Maharashtra,
IN) ; Mereddy; Venkatram R.; (Duluth, MN) |
Correspondence
Address: |
WELLS ST. JOHN P.S.
601 W. FIRST AVENUE, SUITE 1300
SPOKANE
WA
99201
US
|
Family ID: |
38541921 |
Appl. No.: |
11/985381 |
Filed: |
November 15, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11809821 |
Jun 1, 2007 |
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11985381 |
Nov 15, 2007 |
|
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60810408 |
Jun 2, 2006 |
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Current U.S.
Class: |
568/841 |
Current CPC
Class: |
C07C 303/24 20130101;
C07C 29/095 20130101; C07D 303/08 20130101; C07C 67/11 20130101;
C07C 29/095 20130101; C07C 67/11 20130101; C07C 67/11 20130101;
C07D 301/26 20130101; C07C 303/24 20130101; C07C 69/003 20130101;
C07C 31/34 20130101; C07C 69/63 20130101; C07C 305/08 20130101 |
Class at
Publication: |
568/841 |
International
Class: |
C07C 31/34 20060101
C07C031/34 |
Claims
1-49. (canceled)
50: A method of preparing an epoxide comprising: combining a
sulfuric acid containing solution with a halogen to produce a first
mixture; exposing the first mixture to trifluoropropene to produce
a second mixture; combining the second mixture with acetic acid to
produce an acetyl halohydrin of the trifluoropropene; hydrolyzing
the acetyl halohydrin to form a halohydrin of trifluoropropene; and
converting the halohydrin to a trifluoropropyl epoxide.
51: The method of claim 50 wherein the halogen is Br.sub.2, the
acetyl halohydrin is acetyl bromohydrin, the sulfuric acid
containing solution is oleum, and the halohydrin of
trifluoropropene is the bromohydrin of trifluoropropene.
52: The method of claim 51 wherein the first mixture contains a
ratio of oleum to bromine of at least 1:0.7.
53: The method of claim 51 wherein the first mixture contains a
ratio of oleum to bromine of from about 1:0.7 to about 4:0.7.
54: The method of claim 51 wherein the first mixture contains a
ratio of oleum to bromine of about 2:0.8.
55: The method of claim 50 wherein the exposing comprises
maintaining the first mixture at a temperature of from about
12.degree. C. to about 22.degree. C. while bubbling the
trifluoropropene into the first mixture.
56: The method of claim 51 wherein the second mixture comprises
(CF.sub.3CHBrCH.sub.2O--)SO.sub.2.
57: The method of claim 51 wherein the hydrolyzing comprises
exposing the acetyl bromohydrin to a sulfuric acid solution.
58: The method of claim 57 wherein the sulfuric acid solution
comprises at least about 15% (wt./wt.) sulfuric acid.
59: The method of claim 51 wherein the converting comprises
exposing the bromohydrin to a basic solution.
60: The method of claim 59 wherein the basic solution comprises at
least about 20% (wt./wt.) sodium hydroxide.
61: The method of claim 59 wherein the basic solution comprises
from about 40% (wt./wt.) to about 70% (wt./wt.) sodium
hydroxide.
62: The method of claim 59 wherein the basic solution comprises
from about 50% (wt./wt.) to about 60% (wt./wt.) sodium
hydroxide.
63: The method of claim 50 wherein the converting occurs at a
temperature of at least about 100.degree. C.
64: The method of claim 50 wherein the converting occurs at a
temperature of from about 100.degree. C. to about 130.degree. C.
Description
RELATED PATENT DATA
[0001] This patent is a divisional of U.S. patent application Ser.
No. 11/809,821, which was filed Jun. 1, 2007, which claims priority
to U.S. provisional patent application 60/810,408, which was filed
Jun. 2, 2006, entitled "Methods for Preparing Halohydrins and
Methods for Preparing Epoxides" all of which are incorporated by
reference herein.
TECHNICAL FIELD
[0002] The present invention relates to methods for preparing
halohydrins and methods for preparing epoxides.
BACKGROUND OF THE INVENTION
[0003] Polymers can be produced by polymerizing monomers having
epoxide functionality. Monomers having epoxide functionality can be
produced from monomers having halogenated carbons and hydroxyl
groups situated adjacent the halogenated carbon. Compounds having
this functionality are referred to as halohydrins. An exemplary
halohydrin is CF.sub.3CHBrCH.sub.2OH.
[0004] Methods for preparing halohydrins and are provided.
SUMMARY OF THE INVENTION
[0005] The present invention provides methods for preparing
halohydrins and epoxides. In one implementation, a method of
preparing halohydrins includes exposing
(R.sup.1CHXCH.sub.2O--).sub.2SO.sub.2 to R.sup.2COOH to produce
R.sup.2COOCH.sub.2CHXR.sup.1 and hydrolyzing the
R.sup.2COOCH.sub.2CHXOR.sup.1 to produce the halohydrin
R.sup.1CHXCH.sub.2OH. R.sup.1 and R.sup.2 can be the same or
different single elements and/or organic groups and X can be a
halogen.
[0006] In one implementation, a method of preparing a halohydrin
includes exposing a di(perhaloalkyl)haloethyl sulfate to a
carboxylic acid compound to produce a (perhaloalkyl)haloethyl alkyl
ester, and subsequently hydrolyzing the (perhaloalkyl)haloethyl
alkyl ester to produce the halohydrin.
[0007] In one implementation, a method of preparing an epoxide
includes combining a sulfuric acid containing solution with a
halogen to produce a first mixture and exposing the first mixture
to trifluoropropene (TFP) to produce a second mixture. The second
mixture can be combined with acetic acid to produce an acetyl
halohydrin of trifluoropropene and the acetyl halohydrin can be
hydrolyzed to form a halohydrin of trifluoropropene. The halohydrin
can be converted to a trifluoropropyl epoxide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Preferred embodiments of the invention are described below
with reference to the following accompanying drawing.
[0009] The FIGURE is an illustration of a synthetic scheme
according to one aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] This disclosure of the invention is submitted in furtherance
of the constitutional purposes of the U.S. Patent Laws "to promote
the progress of science and useful arts" (Article 1, Section
8).
[0011] In one aspect the present invention includes methods for
preparing halohydrins. Another aspect of the present invention
includes methods for preparing epoxides. Various exemplary aspects
of the present invention are described with reference to the
FIGURE. The FIGURE depicts a synthetic scheme according to one
aspect of the present invention for producing halohydrins and
epoxides. In this exemplary depiction a four step synthetic scheme
is illustrated (with the steps being A, B, C, and D, respectively).
The present invention is not limited to this four step synthetic
scheme. Persons having ordinary skill in the art will be able to
modify and combine synthetic steps using the detailed description
of the present invention.
[0012] Synthetic step A depicts the conversion of an olefin to a
sulfate. The olefin can include compounds having the generic
formula R.sup.1CH.dbd.CH.sub.2. R.sup.1 can include organic groups
such as CF.sub.3-- or single elements such as H and/or halogens
such as I, Br, Cl, or F. It has been generalized to include every
possible olefin. R.sup.1 can also include saturated and unsaturated
carbon chains of organic compounds. An exemplary olefin for use in
accordance with the present invention can be trifluoropropene
(CF.sub.3CH.dbd.CH.sub.2). The conversion of the olefin to the
sulfate can include exposing the olefin to a halogen and sulfuric
acid. The sulfuric acid can be in the form of a solution. An
exemplary sulfuric acid containing solution can be oleum. Oleum can
be a solution of H.sub.2SO.sub.4 that includes free SO.sub.3 and up
to as high as 80% (wt./wt.) free SO.sub.3. The halogen can be
provided in diatomic form, such as, for example, 12, Br.sub.2, or
Cl.sub.2.
[0013] The halogen and oleum can be in the form of a halogen-oleum
mixture. The halogen-oleum mixture can be prepared by combining the
halogen with oleum. The halogen-oleum mixture can include a
Br.sub.2-oleum mixture. The Br.sub.2-oleum mixture can contain at
least about 20% (wt./wt.) oleum. The oleum to bromine mole ratio of
the Br.sub.2-oleum mixture, in one aspect, can be at least 1:0.7,
in another aspect, from about 1:0.7 to about 4:0.7 and, in a
further aspect, can be about 2:0.8.
[0014] In an exemplary aspect, the olefin can be exposed to the
halogen and oleum by bubbling the olefin in gas form into the
halogen-oleum mixture. The olefin can also be exposed to the
halogen-oleum mixture at a temperature from about 12.degree. C. to
about 22.degree. C. The mole ratio of the olefin, the oleum, and
the Br.sub.2 during exposing, in one aspect, can be from about
1:1:0.7 to about 1:4:0.8 and in another aspect, at least about
1:2:0.8.
[0015] A sulfate can be produced upon exposure of the olefin to the
halogen-oleum mixture. The sulfate can have the general formula
(R.sup.1CHXCH.sub.2O--).sub.2SO.sub.2.
[0016] (R.sup.1CHXCH.sub.2O--).sub.2SO.sub.2 can include
di(perhaloalkyl)haloethyl sulfates and more particularly
(CF.sub.3CHXCH.sub.2O--).sub.2SO.sub.2 and even more particularly
(CF.sub.3CHBrCH.sub.2O--).sub.2SO.sub.2. In an exemplary aspect,
(CF.sub.3CHBrCH.sub.2O--).sub.2SO.sub.2 can be produced upon
exposure of trifluoropropene to a Br.sub.2-oleum mixture.
[0017] Referring next to scheme B of the FIGURE, an acetyl
halohydrin can be produced, in an exemplary aspect, upon exposure
the sulfate to a carboxylic acid compound. The carboxylic acid
compound generally has the formula R.sup.2COOH. R.sup.2 can include
the functional group CH.sub.3--, but may also include branched
organic groups such as (CH.sub.3).sub.2CH--. R.sup.2 can also
include single elements such as H and/or halogens such as 1, Br,
Cl, or F. R.sup.2 can be the same or different from R.sup.1. An
exemplary carboxylic acid compound includes acetic acid.
[0018] The acetyl halohydrin can have the general formula
R.sup.2COOCH.sub.2CHXR.sup.1. R.sup.2COOCH.sub.2CHXR.sup.1 also
includes (perhaloalkyl)haloethyl alkyl esters. Exemplary acetyl
halohydrins include R.sup.2COOCH.sub.2CHBrR.sup.1,
CH.sub.3COOCH.sub.2CHXCF.sub.3 and more particularly
CH.sub.3COOCH.sub.2CHBrCF.sub.3. R.sup.2COOCH.sub.2CHBrR.sup.1 can
generally be referred to as an acetyl bromohydrin.
[0019] Referring next to scheme C of the FIGURE, the acetyl
halohydrin is hydrolyzed in one aspect to produce the halohydrin.
In one implementation, the acetyl halohydrin can be hydrolyzed by
exposing the acetyl halohydrin to a sulfuric acid solution. An
exemplary sulfuric acid solution includes at least about 15%
(wt./wt.) sulfuric acid. The halohydrin can have the general
formula R.sup.1CHXCH.sub.2OH. R.sup.1CHXCH.sub.2OH can include
CF.sub.3CHXCH.sub.2OH as well as CF.sub.3CHBrCH.sub.2OH.
R.sup.1CHBrCH.sub.2OH can generally be referred to as a
bromohydrin.
[0020] Referring to scheme D of the FIGURE, the halohydrin can be
converted in one aspect to an epoxide in the presence of a base. In
an exemplary aspect the halohydrin is exposed to a basic solution
to produce the epoxide. The basic solution can comprise at least
about 20% (wt./wt.) sodium hydroxide and/or from about 40% to about
70% sodium hydroxide as well as from about 50% to about 60% sodium
hydroxide. The conversion of the halohydrin to the epoxide can also
occur at a temperature of at least about 100.degree. C. or from
about 100.degree. C. to about 130.degree. C. The epoxide can have
the general formula R.sup.1CHCH.sub.2(O). R.sup.1CHCH.sub.2(O) can
also include CF.sub.3CHCH.sub.2(O) and trifluoropropyl epoxide. In
an exemplary embodiment (not shown) the epoxide may be utilized as
a monomer in the production of polymers. An exemplary polymer can
include fluoropolymers having at least one CF.sub.3-- group.
[0021] Aspects of the present invention will now be described with
reference to the following non-limiting examples.
Example 1
[0022] ##STR1## TABLE-US-00001 TABLE 1 MW Mmoles equivalents
Quantity TFP 96 0.186 1 18 g Oleum 20% 0.375 2 150 g Br.sub.2 160
0.180 0.97 28.7 g CH.sub.3COOH n/a n/a n/a 300 ml
[0023] In accordance with example 1, 150 g of oleum is taken in a
500 ml three-necked round-bottomed flask fitted with a dry ice
condenser and a bubbler (TFP inlet tube) to which 28.7 g. Br.sub.2
is then added to form a bromine-oleum mixture. The bromine-oleum
mixture is stirred at room temperature for 3 hrs. The
round-bottomed flask is covered with aluminum foil. TFP (18 g) is
then bubbled through the mixture to form a reaction mixture. The
rate of TFP addition is adjusted so that the temperature of the
reaction mixture remains from about 12.degree. C. to about
22.degree. C. Upon addition of the TFP the bromine color is nearly
gone, and the reaction mixture is stirred at room temperature for 1
hour. The reaction mixture is then poured into 300 ml of acetic
acid taken in a 500 ml single-neck round-bottomed flask, stirred,
and heated to 100.degree. C. for 1 hr. This solution is cooled to
room temperature and 100 ml of water is added and extracted four
times with 100 ml portions of dichloromethane. (Dichloromethane
forms an upper layer). Organic layers are combined and washed with
saturated NaHCO.sub.3 (4.times.200 ml), dried over anhydrous
Na.sub.2SO.sub.4 (150 g.) and evaporated (without applying vacuum)
to yield acetyl bromohydrin (43.9 g.) as a clear colorless liquid.
Yield=43.9 g. (99.6%), .sup.1H NMR: (CDCl.sub.3, 300 MHz), .delta.
ppm: 2.12 (s, 3H), 4.34-4.56 (m, 3H)
Example 2
[0024] ##STR2## TABLE-US-00002 Acetyl bromohydrin 180 g. Conc.
H.sub.2SO.sub.4 100 ml H.sub.2O 1000 ml
[0025] In accordance with example 2, 1 L of water is placed in a 2
L single-necked round-bottomed flask fitted with a condenser.
Concentrated H.sub.2SO.sub.4 (100 ml) is added slowly to the flask
to produce a reaction mixture. Acetyl bromohydrin (180 g) is then
added and the mixture is heated to reflux. The mixture is refluxed
for 3 hrs until the mixture becomes homogeneous and further
refluxed for 1 hour and then cooled to room temperature. The
reaction mixture is saturated with NaCl and extracted with ether
(200 ml.times.5). Combined ether layers are washed with saturated
NaHCO.sub.3, dried over anhydrous Na.sub.2SO.sub.4 and evaporated
to yield bromohydrin 131 g. Yield=131 g. (89%) .sup.1H NMR
(CDCl.sub.3, 300 MHz) .delta. ppm: 3.90-4.02 (m, 1H), 4.04-4.14 (m,
1H), 4.22-4.34 (m, 1H).
Example 3
[0026] ##STR3## TABLE-US-00003 Bromohydrin 65 g. Aq. NaOH (20%) 100
g.
[0027] In accordance with example 3, 65 g. bromohydrin is taken in
a 300 ml three-necked round-bottomed flask fitted with a septum, a
thermometer jacket, and a distillation set up. The bromohydrin is
stirred and heated to 85.degree. C. (oil bath temperature was
95.degree. C.). NaOH (20% solution, 100 g) is introduced through
septum by syringe. Product distills as NaOH is introduced. Yield=26
g. (69%) .sup.1H NMR: (CDCl.sub.3, 300 MHz) .delta. ppm: 2.90-2.94
(m, 1H), 2.96-3.02 (m, 1H), 3.38-3.46 (m, 1H).
[0028] In compliance with the statute, the invention has been
described in language more or less specific as to structural and
methodical features. It is to be understood, however, that the
invention is not limited to the specific features shown and
described, since the means herein disclosed comprise preferred
forms of putting the invention into effect. The invention is,
therefore, claimed in any of its forms or modifications within the
proper scope of the appended claims appropriately interpreted in
accordance with the doctrine of equivalents.
* * * * *