1-(5-Tert-butoxy-2-isopropoxy-benzothiazol-7-yl)-2-chloro-ethanone → (R)-1-(5-tert-Butoxy-2-isopropoxy-benzothiazol-7-yl)-2-chloro-ethanol

Participants

Reaction Conditions

Reaction Steps

A suspension of 1-(5-tert-butoxy-2-isopropoxybenzo[d]thiazol-7-yl)-2-chloro-ethanone (70 g, 204.8 mmol) and RuCl(p-cymene)[(S,S)-Ts-DPEN] (1.954 g, 3.07 mmol) in methanol/DMF (1330 ml/70 ml) was degassed and refilled with N2 three times. A degassed preformed mixture of formic acid (28.3 g) in Et3N (124.3 g) was added slowly while keeping the internal temperature between 15 to 20° C. The resulting yellow suspension was warmed up to 30° C. After 2 h the reaction mixture is cooled to 25° C., water (750 ml) was then added into the reaction mixture followed by the addition of acetic acid (56 ml) in one portion. The mixture was concentrated and then diluted with TBME (1000 ml). Aqueous phase was separated and extracted with TBME (1000 ml). The combined organic phase was washed sequentially with water and brine and then dried with Na2SO4 and concentrated under vacuum to give (R)-1-(5-tert-Butoxy-2-isopropoxy-benzothiazol-7-yl)-2-chloro-ethanol (72 g).

Provenance & Evidence