US4461911A
Expired / Lapsed
US
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Process for the preparation of S-arylthioglycolic acids
Assignee: Bayer AG
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Filing: 1982-05-26
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Granted: 1984-07-24
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Expires: 2002-05-26
Abstract
Abstract Process for the preparation of S-arylthioglycolic acids of the formula ##STR1## in which A designates a benzene ring, which can be substituted by 1, 2, 3, 4 or 5 substituents from the series halogen, nitro, hydroxyl, mercapto, trifluoromethyl, alkyl, aryl, alkoxy, aryloxy, acylamino, alkylamino, arylamino, alkylmercapto, arylmercapto, cyano, carboxyl, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl or optionally substituted aminocarbonyl, or represents a benzene ring, which optionally carries 1 or 2 of the previously mentioned substituents, to which a carbocyclic or heterocyclic aromatic ring is attached, characterized in that aryldiazonium salts of the formula ##STR2## in which A has the meanings given for the formula (I) and X designates the radical of an acid capable of forming a salt with the diazonium cation, are reacted with thioglycolic acid in an aqueous acid medium in the presence of Cu(I) or Cu(II) salts and the reaction mixture is worked up to compounds of the formula (I) or their salts.
Inventors
- 👤 Detlef-Ingo Schutze
- 👤 Anton Adams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:19
CPC Classifications
C; C07; C07C; C07C321/00
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
181 words
Process for the preparation of S-arylthioglycolic acids of the formula ##STR23## in which A designates a benzene ring, which can be substituted by 1, 2, 3, 4 or 5 substituents selected from the group consisting of halogen, nitro, hydroxyl, mercapto, trifluoromethyl, alkyl, aryl, alkoxy, aryloxy, acylamino, alkylamino, arylamino, alkylmercapto, arylmercapto, cyano, carboxyl, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, unsubstituted aminocarbonyl and aminocarbonyl which is mono- or di-substituted on the N-atom by C 1 -C 6 -alkyl or phenyl, or A represents an unsubstituted benzene ring or a substituted benzene ring, which carries 1 or 2 of the previously mentioned substituents, to which a carbocyclic or heterocyclic aromatic ring is fused to A, wherein aryldiazonium salts of the formula ##STR24## in which A has the meanings given for the formula (I) and X designates the radical of an acid capable of forming a salt with the diazonium cation, are reacted with thioglycolic acid in an aqueous acid medium in the present of Cu(I) or Cu(II) salts, and the reaction is allowed to proceed such that the reaction mixture forms compounds of the formula (I).
Claim 2
Dependent Claim
181 words
Process for the preparation of S-arylthioglycolic acids of the formula ##STR23## in which A designates a benzene ring, which can be substituted by 1, 2, 3, 4 or 5 substituents selected from the group consisting of halogen, nitro, hydroxyl, mercapto, trifluoromethyl, alkyl, aryl, alkoxy, aryloxy, acylamino, alkylamino, arylamino, alkylmercapto, arylmercapto, cyano, carboxyl, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, unsubstituted aminocarbonyl and aminocarbonyl which is mono- or di-substituted on the N-atom by C 1 -C 6 -alkyl or phenyl, or A represents an unsubstituted benzene ring or a substituted benzene ring, which carries 1 or 2 of the previously mentioned substituents, to which a carbocyclic or heterocyclic aromatic ring is fused to A, wherein aryldiazonium salts of the formula ##STR24## in which A has the meanings given for the formula (I) and X designates the radical of an acid capable of forming a salt with the diazonium cation, are reacted with thioglycolic acid in an aqueous acid medium in the present of Cu(I) or Cu(II) salts, and the reaction is allowed to proceed such that the reaction mixture forms compounds of the formula (I).
Claim 3
Dependent Claim
59 words
Process according to claim 1 for the preparation of S-arylthioglycolic acids of the formula ##STR25## in which A' designates as a benzene ring, which can be substituted by 1, 2 or 3 substituents selected from the group consisting of halogen, alkyl, alkoxy, carboxyl, nitro and trifluoromethyl, or A' designates a benzene ring to which another benzene ring is fused.
Claim 4
Dependent Claim
10 words
Process according to claim 1 for the preparation of ##STR26##
Claim 5
Dependent Claim
11 words
Process according to claim 1, wherein copper (II) salts are employed.
Claim 6
Dependent Claim
24 words
Process according to claim 1, wherein copper (II) chloride, copper (II) bromide, copper(II) iodide, copper(II) sulphate, copper(II) acetate or basic copper(II) carbonate is employed.
Claim 7
Dependent Claim
18 words
Process according to claim 1, wherein the reaction is carried out at a pH between 0 and 4.5.
Claim 8
Dependent Claim
21 words
Process according to claim 1, wherein the reaction is carried out at a temperature of about 0° to about 70° C.
Claim 9
Dependent Claim
20 words
Process according to claim 1, wherein 1 to 1.8 mol of thioglycolic acid are employed per mol of aryldiazonium salt.
Claim 10
Dependent Claim
20 words
Process according to claim 1, wherein 0.1 to 1.2 mol of copper salt are employed per mol of aryldiazonium salt.
Claim 11
Dependent Claim
37 words
Process according to claim 1, wherein the reaction mixture containing the synthesized acid is made alkaline, whereby to convert said S-arylthioglycolic acid to the corresponding salt which becomes dissolved in said solution and the copper is precipitated.
Claim 12
Dependent Claim
24 words
Process according to claim 10, wherein the copper precipitate is separated off and the S-arylthioglycolic moiety is precipitated by addition of acid and isolated.
Claim 13
Dependent Claim
18 words
Process according to claim 1, wherein the reaction is carried out at a pH between 0.5 and 1.5.
Claim 14
Dependent Claim
22 words
Process according to claim 1, wherein the reaction is carried out at a temperature of about 20° C. to about 30° C.
Claim 15
Dependent Claim
20 words
Process according to claim 1, wherein 1.2 to 1.5 mol of thioglycolic acid are employed per mol of aryldiazonium salt.
Claim 16
Dependent Claim
20 words
Process according to claim 1, wherein 0.6 to 1 mol of copper salt are employed per mol of aryldiazonium salt.
Claim 17
Dependent Claim
10 words
Process according to claim 2, wherein said halogen is chlorine.
Claim 18
Dependent Claim
18 words
Process according to claim 2, wherein said alkyl is selected from the group consisting of methyl and ethyl.
Claim 19
Dependent Claim
18 words
Process according to claim 2, wherein said alkoxy is selected from the group consisting of methoxy and ethoxy.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-24 | 1988-01-23 | 1988-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-24 | 1992-01-23 | 1992-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-24 | 1996-01-23 | 1996-07-24 | $7700.00 | Window Closed / Lapsed |