Benzyl chloroformate → 1-Carbobenzyloxyamino-2-methylpropanephosphonous acid

Participants

Reaction Steps

27.5 parts of DL-1-amino-2-methylpropanephosphonous acid in 100 parts of water was stirred until solution occurred. The pH of the solution was adjusted to 9.5 with 4N sodium hydroxide and the mixture cooled to 0°. 34 Parts of benzyl chloroformate was added over 1 hour and the mixture stirred for 6 hours maintaining at pH 9.0-9.5 by periodic addition of 4N sodium hydroxide. The mixture was allowed to warm up to room temperature and then washed with ether. The aqueous portion was added slowly to a mixture of 120 parts of water and 80 parts of concentrated hydrochloric acid and 400 parts of ice. The solid which was obtained was dried and recrystallised from ethyl acetate/petroleum ether to give DL-1-carbobenzyloxyamino-2-methylpropanephosphonous acid, melting point 108°-111°.

Provenance & Evidence