Lipoic acid → alpha Lipoic acid

HRID 1604449Notes

Reaction equation

HRID 1604449 reaction equation
[CH2:1]1[C@@H:5]([CH2:6][CH2:7][CH2:8][CH2:9][C:10]([OH:12])=[O:11])[S:4][S:3][CH2:2]1>C1(C)C=CC=CC=1.CCCCCCC>[CH2:1]1[CH:5]([CH2:6][CH2:7][CH2:8][CH2:9][C:10]([OH:12])=[O:11])[S:4][S:3][CH2:2]1

Participants

4

Reactant 1

HCID 6112Lipoic acid

Product 1

HCID 864alpha Lipoic acidYield 66.7%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8900HeptaneSolvent

Conditions

Temperature
-7.5 °C

Procedure

A solution which contained 19.5 g R-(+)-thioctic acid and 0.5 g S-(-)-thioctic acid in a mixture of 24 ml toluene and 6 ml n-heptane was cooled off from 35 to 40° C. down to -5 to -10° C., filtered and dried. 13.0 g thioctic acid were obtained in the novel modification as first crystallizate. The R-(+)-thioctic acid content was 94.5% with a melting range of 45 to 48° C.

Workup

  1. filtrationfiltered
  2. customdried

Sources & evidence

ORD record
ord-db369030afa64cd9a5bf6e28c0100ce7
Source dataset
uspto-grants-1999_11
Patent number
US05994393

Reaction notes

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