Title:
PROCESS FOR THE PRODUCTION OF RACEMIC THIOCTIC ACID
Document Type and Number:
WIPO Patent Application WO2002030917
Kind Code:
A3
Abstract:
Process for the synthesis of racemic thiotic acid comprising the following stages: a) reaction of the alkyl ester of 6,8-di-halo-octanoic acid in an organic solvent with an aqueous solution of alkali disulfide in presence of a compound for phase transfer catalysis selected from the group consisting of quaternary ammonium or phosphonium salts having the following general formula: where: A is nitrogen of phosphorus, X is selected from the group consisting of Cl, Br, I, HSO4, and H2PO4 and the substitutents R1, R2, R3 and R4 are selection from the group consisting of linear or branched alkyl radicals having one to twenty carbon atoms (C1-C20), said substituents being identical or different one from the other, or only one of said substituents is selected from the group consisting of arylalkyl radicals having the following formula -(CH2)nC6H5 in which n=1-16; b) followed by the hydrolysis of the ester of racemic thiotic acid.
Inventors:
SALVI ANNIBALE (IT)
MAIORANA STEFANO (IT)
CORCELLA FRANCESCO (IT)
MAIORANA STEFANO (IT)
CORCELLA FRANCESCO (IT)
Application Number:
PCT/EP2001/011577
Publication Date:
July 25, 2002
Filing Date:
October 08, 2001
Export Citation:
Assignee:
LABORATORIO CHIMICO INT SPA (IT)
SALVI ANNIBALE (IT)
MAIORANA STEFANO (IT)
CORCELLA FRANCESCO (IT)
SALVI ANNIBALE (IT)
MAIORANA STEFANO (IT)
CORCELLA FRANCESCO (IT)
International Classes:
C07D339/04; (IPC1-7): C07D339/04; C07C319/06
Foreign References:
| US6140512A | 2000-10-31 | |||
| US2792406A | 1957-05-14 |
Other References:
BRINGMANN G ET AL: "A SHORT AND PRODUCTIVE SYNTHESIS OF (R)-ALPHA-LIPOIC ACID", ZEITSCHRIFT FUR NATURFORSCHUNG, TEIL B: ANORGANISCHE CHEMIE, ORGANISCHE CHEMIE, VERLAG DER ZEITSCHRIFT FUR NATURFORSCHUNG. TUBINGEN, DE, NR. 54B, PAGE(S) 655-661, ISSN: 0932-0776, XP001063331
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