Lipoic acid → alpha Lipoic acid

Participants

Reaction Conditions

Reaction Steps

A solution which contained 17.5 g R-(+)-thioctic acid and 2.5 g S-(-)-thioctic acid in a mixture of 200 ml n-hexane and 57 ml ethyl acetate was cooled off from 35 to 40° C. down to -5 to -10° C., filtered and dried. 13.5 g thioctic acid were obtained in the novel modification as first crystallizate. The R-(+)-thioctic acid content was 82.6% with a melting range of 47 to 52° C.

Provenance & Evidence