Methyl chloroformate → N-Benzyloxy-t-butoxycarbonyl-threonine amide

Participants

Reaction Conditions

Reaction Steps

N-(t-Butyloxycarbonyl)-L-threonine (82.2 g) was dissolved in 1 liter of ethyl acetate and 40.5 g of dimethyl (phenylmethyl)amine was added. After stirring for 10 minutes the mixture was cooled to -10° C. and 31.05 g of methyl chloroformate were added dropwise. The mixture was stirred for 30 minutes at -10° C., after which a solution of 40.65 g of (phenylmethoxy)amine in 300 ml of ethyl acetate was added at -10° C. The temperature was then permitted to rise to 5° C. during a 90 minute period. The reaction mixture was evaporated in vacuo and redissolved in 1 liter of ethyl acetate the insoluble material was filtered off and the filtrate washed, with cooling, with water, dilute hydrochloric acid, (pH of aqueous phase not less than 2.5), sodium bicarbonate solution and brine. After drying (MgSO4) the solvent was removed in vacuo to yield an oil, which crystallized on treatment with petroleum ether, yielding 79.4 g of the title compound, melting point 87° C.

Provenance & Evidence