Claims
- 1. In a process for the preparation of an ester of mercaptocarboxylic acid of formula:HS—X—COOR (I) in which X denotes a linear or branched alkylene radical containing from 1 to 4 carbon atoms and R a linear or branched alkyl radical containing from 1 to 18 carbon atoms, comprising reacting ammonium hydrosulphide or an alkali or alkaline-earth metal hydrosulphide with the corresponding halocarboxylic ester of formula:Y—X—COOR (II) in which R and X have the same meanings as above and Y denotes a chlorine or bromine atom, the improvement comprising conducting the reaction under a hydrogen sulphide pressure of at least 10 bars absolute and at a temperature from 10 to 40° C.
- 2. A process according to claim 1, in which the hydrogen sulphide pressure is between 10 and 20 bars absolute.
- 3. A process according to claim 1, in which the hydrosulphide/ester (II) molar ratio is between 1 and 2.
- 4. A process according to claim 1, in which ammonium hydrosulphide is employed.
- 5. A process according to claim 1, in which the hydrosulphide/ester (II) molar ratio is between 1.1 and 1.5.
- 6. A process according to claim 1, wherein the medium is anhydrous.
- 7. A process according to claim 6, in which the alcohol is methanol or isopropanol.
Priority Claims (1)
Number |
Date |
Country |
Kind |
94 10145 |
Aug 1994 |
FR |
|
Parent Case Info
This application is a continuation of U.S. application Ser. No. 09/063,399, filed Apr. 21, 1998 now abondoned, which is a divisional of Ser. No. 08/516,699, filed Aug. 18, 1995 now U.S. Pat. No. 5,773,641 both of which applications are incorporated by reference herein in their entirety.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
2262686 |
Kyrides et al. |
Nov 1941 |
|
3927085 |
Zengel et al. |
Dec 1975 |
|
5773641 |
Labat et al. |
Jun 1998 |
|
Non-Patent Literature Citations (6)
Entry |
R.M. Acheson et al., “The Synthesis of Some Thiophens Related to . . . ”, J.C.S., pp. 650-660, 1961. |
Translation Of Chemical Abstract, JP 63-10755, published Jan. 18, 1988. |
Translation of Chemical Abstract, Abstract No. 59499z, vol. 80(11), JP-48-86818, published Nov. 15, 1973. |
Acheson et al.. “The Synthesis of Some Thioplens Related to Vitamin A”, J.C.S. 1161 (pp. 650-660), 1961. |
Translation of JP 48-86818. 1973. |
Translation of JP 63-10755. 1988. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
09/063399 |
Apr 1998 |
US |
Child |
09/567087 |
|
US |