U.S. patent application number 11/253798 was filed with the patent office on 2006-04-27 for cyclobutanetetracarboxylate compound and preparation method thereof.
This patent application is currently assigned to ETERNAL CHEMICAL CO., LTD.. Invention is credited to Chia-Wen Chang, Ming-Chih Lai, Chi-Wi Ong.
Application Number | 20060089505 11/253798 |
Document ID | / |
Family ID | 36206993 |
Filed Date | 2006-04-27 |
United States Patent
Application |
20060089505 |
Kind Code |
A1 |
Lai; Ming-Chih ; et
al. |
April 27, 2006 |
Cyclobutanetetracarboxylate compound and preparation method
thereof
Abstract
The invention provides a cyclobutanetetracarboxylate compound of
general formula (I) and a preparation method thereof: ##STR1## in
which R and R.sub.1 are as defined in the specification.
Inventors: |
Lai; Ming-Chih; (Kaohsiung,
TW) ; Chang; Chia-Wen; (Kaohsiung, TW) ; Ong;
Chi-Wi; (Kaohsiung, TW) |
Correspondence
Address: |
LADAS & PARRY
26 WEST 61ST STREET
NEW YORK
NY
10023
US
|
Assignee: |
ETERNAL CHEMICAL CO., LTD.
|
Family ID: |
36206993 |
Appl. No.: |
11/253798 |
Filed: |
October 19, 2005 |
Current U.S.
Class: |
560/123 |
Current CPC
Class: |
C07C 67/347 20130101;
C07C 2601/04 20170501; C07C 69/74 20130101; C07C 69/74 20130101;
C07C 67/347 20130101 |
Class at
Publication: |
560/123 |
International
Class: |
C07C 67/347 20060101
C07C067/347; C07C 69/74 20060101 C07C069/74 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 2004 |
TW |
093131887 |
Claims
1. A cyclobutanetetracarboxylate compound of general formula (I):
##STR5## in which: R can be the same or R is different from each
other and independently represents hydrogen or a halogen or a
monovalent organic radical; and R.sub.1 is a C.sub.1-C.sub.4
alkyl.
2. The cyclobutanetetracarboxylate compound of claim 1, wherein
said monovalent organic radical is a straight-chained, branched, or
cyclic C.sub.1-C.sub.4 alkyl.
3. The cyclobutanetetracarboxylate compound of claim 1, wherein
said monovalent organic radical is methyl, ethyl, propyl,
isopropyl, butyl, or isobutyl.
4. A process for the preparation of the cyclobutanetetracarboxylate
compound as defined in claim 1, comprising: (a) conducting an
esterification reaction of a diacid compound of general formula
(II) ##STR6## (in which R is as defined hereinbefore) with an
alcohol of general formula (III) R.sub.1--OH Formula (III) in the
presence of an acidic solvent to obtain a precursor compound of
general formula (IV) ##STR7## (b) conducting a cyclization reaction
by irradiating the precursor compound of general formula (IV) with
an energy ray to obtain the cyclobutanetetracarboxylate compound of
general formula (I).
5. The process of claim 4 wherein the alcohol of general formula
(III) is methanol, ethanol, propanol, or isopropanol.
6. The process of claim 4 wherein the reaction of step (a) is
conducted at a temperature from 60 to 110.degree. C.
7. The process of claim 4 wherein the reaction of step (a) is
conducted for 2 to 20 hours.
8. The process of claim 4 wherein the energy ray used in step (b)
is a light source having a wavelength of from 200 to 600 nm.
9. The process of claim 4 wherein the energy ray used in step (b)
is an ultraviolet light.
10. The process of claim 4 wherein the reaction of step (b) is
conducted for 30 minutes to 30 hours.
11. The process of claim 4 wherein the reaction of step (b) is
conducted in the presence of a solvent.
12. The process of claim 11 wherein the solvent is ethyl acetate,
acetone, water, or methanol, or a mixture thereof.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a
cyclobutanetetracarboxylate compound and a preparation method
thereof.
[0003] 2. Description of the Prior Art
[0004] Cyclobutanetetracarboxylic dianhydrides are important
monomer materials for the preparation of an alignment film useful
for flat panel displays. Japanese Laid-open Hei 2003-192685
discloses a process for producing cyclobutanetetracarboxylic
dianhydride comprising irradiating maleic anhydride to synthesize
the cyclobutanetetracarboxylic dianhydride. This process, however,
suffers from the shortcomings of a low yield in the production of
the butane structure.
[0005] To overcome the above shortcomings, the inventors of the
subject application developed a new synthesis route comprising
synthesizing a cyclobutanetetracarboxylate, hydrolyzing the
cyclobutanetetracarboxylate, and dehydrating the hydrolyzed product
to obtain the corresponding cyclobutanetetracarboxylic dianhydride.
The new route according to the present invention achieves an
improved yield of the desired compounds.
SUMMARY OF THE INVENTION
[0006] One of the objects of the invention is to provide a
cyclobutanetetracarboxylate compound.
[0007] Another object of the invention is to provide a process for
preparing the cyclobutanetetracarboxylate compound.
DETAILED DESCRIPTION OF THE INVENTION
[0008] The invention provides a cyclobutanetetracarboxylate
compound of the general formula (I): ##STR2## in which: [0009] R
can be the same or R is different from each other and independently
represents hydrogen or a halogen or a monovalent organic radical;
and R.sub.1 is a C.sub.1-C.sub.4 alkyl.
[0010] There are no special requirements for the species of the
monovalent organic radical suitable for the present invention.
Preferably, the monovalent organic radical is a C1-C4 alkyl, which
can be straight-chained, branched, or cyclic; and more preferably,
is methyl, ethyl, propyl, isopropyl, butyl, or isobutyl.
[0011] The invention further provides a process for preparing the
cyclobutanetetracarboxylate compound of formula (I). The inventive
process comprises the steps of:
[0012] (a) conducting an esterification reaction of a diacid
compound of general formula (II) ##STR3## (in which R is as defined
hereinbefore) with an alcohol of general formula (III) R.sub.1--OH
Formula (III) in the presence of an acidic solvent to obtain a
precursor compound of general formula (IV) ##STR4##
[0013] (b) conducting a cyclization reaction by irradiating the
precursor compound of general formula (IV) with an energy ray to
obtain the cyclobutanetetracarboxylate compound of general formula
(I).
[0014] The acidic solvent used in the inventive process can also be
used as a catalyst to enhance the reaction rate. Suitable acidic
solvent can be a mono-protonic inorganic acid, a multi-protonic
inorganic acid, or an organic acid, which preferably is
hydrochloric acid or sulfuric acid.
[0015] The esterification reaction in step (a) of the inventive
process is obvious to persons skilled in the art. The suitable
species of the alcohol will vary with the desired product to be
obtained and may include, for example, methanol, ethanol, propanol,
or isopropanol. The diacid compound used in the present invention
is a fumaric acid. The esterification reaction is conducted at a
temperature ranging from 60 to 110.degree. C. for 2 to 20
hours.
[0016] The energy ray used in step (b) of the inventive process
refers to a light source with a wavelength of from 200 to 600 nm,
preferably an ultraviolet light. In general, the irradiation time
will vary with the wavelength of the energy ray and is normally in
the range of from about 30 minutes to 30 hours. In addition, if
desired, the reaction of step (b) can be conducted in the presence
of a solvent that is beneficial to the progress of the reaction.
Examples of such solvent include ethyl acetate, acetone, water, or
a mixture thereof.
[0017] The compound of formula (I) according to the present
invention can be catalytically hydrolyzed in the presence of an
acid or a base in a conventional manner known to persons skilled in
the art to form the corresponding cyclobutanetetracarboxylic acid,
which can be further dehydrated to form the corresponding
cyclobutanetetracarboxylic dianhydride.
[0018] The present invention will be further described in the
following example. However, the example will not make any
limitations to the scope of the invention. Any modifications or
alterations on the invention that can be easily accomplished by
persons skilled in the art are encompassed in the disclosure of the
specification and the accompanying claims.
EXAMPLE
Synthesis of a cyclobutanetetracarboxylic dianhydride
[0019] In a 5-liter flask, methanol (3000 ml, 75 mol) and then
fumaric acid (1160 g, 10 mol) and concentrated sulfuric acid (10
ml, 0.2 mol) were added. The reaction was conducted at a controlled
temperature of 75.degree. C. for 10 hours and then cooled to room
temperature. The resultant solid was collected by vacuum filtration
and washed with methanol to obtain dimethyl fumarate (1224 g, 8.5
mol).
[0020] The dimethyl fumarate (1224 g, 8.5 mol) and water (4000 ml)
were added to a 6-liter flask and irradiated by 365 nm ultraviolet
lights for 7 hours. The resultant solid in the flask was vacuum
filtered to obtain tetramethyl cyclobutane-1,2,3,4-tetracarboxylate
(1224 g, 4.25 mol).
[0021] The resultant tetramethyl
cyclobutane-1,2,3,4-tetracarboxylate (1224 g, 4.25 mol) and aqueous
hydrochloric acid (3000 ml) were added to a 5-liter flask; reacted
at a controlled temperature of 85.degree. C. for 24 hours; cooled
to room temperature; concentrated; and dried to obtain
cyclobutane-1,2,3,4-tetracarboxylic acid (870 g, 3.75 mol).
[0022] The cyclobutane-1,2,3,4-tetracarboxylic acid (501 g, 2.16
mol) and acetic anhydride (3000 ml) were added to a 5-liter flask
and reacted at a controlled temperature of 150.degree. C. for 24
hours. The reaction was cooled to room temperature; concentrated;
and dried to obtain 1,2,3,4-cyclobutanetetracarboxylic dianhydride
(573 g, 2.93 mol).
* * * * *