N-[1,1-dimethoxycarbonyl-4-oxo-4-(2-thienyl)butyl]-L-alanyl-L-proline t-butyl ester → N-[1-methoxycarbonyl-4-oxo-4-(2-thienyl)butyl]-L-alanyl-L-proline t-butyl ester

Participants

Reaction Steps

Aqueous N-sodium hydroxide solution (6.2 ml.) was added to a solution of N-[1,1-dimethoxycarbonyl-4-oxo-4-(2-thienyl)butyl]-L-alanyl-L-proline t-butyl ester (Example 31; 3.0 g.) in a mixture of methanol (3 ml.) and water (1.5 ml.) and the mixture was stirred at laboratory temperature for 16 hours and then evaporated to dryness under reduced pressure. The mixture was partitioned between water and ethyl acetate and the aqueous layer was separated, acidified to pH 5 with aqueous N-hydrochloric acid and extracted with dichloromethane. The extract was dried over magnesium sulphate and evaporated to dryness. There was thus obtained as residual oil N-[1-methoxycarbonyl-4-oxo-4-(2-thienyl)butyl]-L-alanyl-L-proline t-butyl ester.

Provenance & Evidence