Lithium hydroxide, monohydrate → N-[(S)-alpha-[[[1-methyl-1-[methyl-[2-(2-pyridyl)ethyl]carbamoyl]ethyl]sulfonyl]methyl]hydrocinnamoyl]-3-(thiazol-4-yl)-D,L-alanine

Participants

Reaction Steps

A solution of 300 mg of N-[(S)-α-[[[1-methyl-1-[methyl-[2-(2-pyridyl)ethyl]carbamoyl]ethyl]sulfonyl]methyl]hydrocinnamoyl]-3-(thiazol-4-yl)-D,L-alanine methyl ester in 2.5 ml of dioxan was treated with a solution of 24.3 mg of lithium hydroxide hydrate in 1 ml of water and stirred at 50 for 3 hours. Subsequently, the solution was partitioned between ethyl acetate and water and the organic phase was extracted three times with water. The aqueous extracts were adjusted to pH 2 with ethyl acetate and with 2N hydrochloric acid and evaporated under reduced pressure. There were obtained 365 mg of N-[(S)-α-[[[1 -methyl-1-[methyl-[2-(2-pyridyl)ethyl]carbamoyl]ethyl]sulfonyl]methyl]hydrocinnamoyl]-3-(thiazol-4-yl)-D ,L-alanine as a colourless foam which was used directly in the next step.

Provenance & Evidence