Chlorosulfonyl isocyanate → Carbamic acid 3-(4-benzyloxy-phenyl)-isoxazol-5-ylmethyl ester

Participants

Reaction Steps

1.04 ml of chlorosulfonyl isocyanate (12 mmol) was slowly added to [3-(4-benzyloxy-phenyl)-isoxazol-5-yl]-methanol (2.813 g, 10 mmol) in THF (50 ml, 0.2 M) in a 250 ml-flask at −78° C. The consumption of all the starting materials was confirmed by liquid chromatography, and then water was added to the reaction mixture. After 1 hour, the THF was distilled off under reduced pressure, and the resulting solid after addition of 100 ml of water to the mixture was filtered off. The filtered solid was each washed with 100 ml of water and a solution of ethyl acetate/hexane (1/2) and then dried to obtain 3.4 g of a crude product (95.9% pure). The crude compound was recrystallized from an ethyl acetate/hexane/methylene chloride (1/4/1) solution containing 1% MeOH to obtain 2.743 g of carbamic acid 3-(4-benzyloxy-phenyl)-isoxazol-5-ylmethyl ester of 99% purity.

Provenance & Evidence