Lipoic acid → alpha Lipoic acid

HRID 1604448Notes

Reaction equation

HRID 1604448 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>CCCCCC.C(OCC)(=O)C>[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 77.1%

Reagents, catalysts & solvents 2

HCID 8058HexaneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
-7.5 °C

Procedure

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.

Workup

  1. filtrationfiltered
  2. customdried

Sources & evidence

ORD record
ord-8694e02128e7469294b5d4af4fa66464
Source dataset
uspto-grants-1999_11
Patent number
US05994393

Reaction notes

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