Hydrochloric Acid → (S-(R*,R*))-3-((o-Aminophenyl)thio)-3-(p-methoxyphenyl)lactic acid

Participants

Reaction Conditions

Reaction Steps

60 g (1.65 mol) of (2S,3S)-2-hydroxy-3-(4-methoxyphenyl)-3-(2-acetylaminophenylthio)propionic acid were suspended in 300 ml of water containing 50 ml of 32% (w/w) hydrochloric acid in the presence of 0.5 g of KI. The mixture was heated to slow reflux for about 3 hours, filtered at about 80° C., separating approximatively 10 g of unsolubles, and the filtered waters were neutralized to pH 6 with 30% (w/w) NaOH, cooled to about 15° C., filtered and thoroughly washed with water. 36 g of (2S,3S)-2-hydroxy-3-(4-methoxyphenyl)-3-(2-aminophenylthio)propionic acid were obtained with 80% optical purity 98-100%. The acid pH hot filtered unsolubles consisted of a mixture of non unhydrolyzed compound and of compound cyclized to benzothiazepine ring.

Provenance & Evidence