Sodium Carbonate → ((S)-5-methanesulfonyl-1-methyl-2-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-yl)-carbamic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

A mixture of 623 mg (3.4 mmol) of methanesulfonic acid anhydride and 0.12 ml (0.7 mmol) of N-ethyl-diisopropylamine was cooled to 0° C. and treated with a solution of 200 mg (0.7 mmol) of (S)-(1-methyl-2-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-yl)-carbamic acid tert-butyl ester in 2 ml of dichloromethane. The reaction mixture was left to warm to room temperature and stirred during 18 h. For the working-up, the reaction mixture was cooled to 0° C. and treated with a saturated solution of sodium carbonate. The organic layer was separated, washed with a saturated solution of ammonium hydrochloride and water, finally dried over sodium sulphate and evaporated. For purification, the crude material was chromatographed on silical gel using a 96:4-mixture of dichloromethane and ethyl acetate as the eluent. There were obtained 100 mg (40% of theory) of the ((S)-5-methanesulfonyl-1-methyl-2-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-yl)-carbamic acid tert-butyl ester as a white foam;

Provenance & Evidence