Methyl chloroformate → HCID 131723425, compound

Participants

Reaction Steps

To a solution of N-boc-(L)-valine (IV, 1.04 g, 4.8 mmol) in dichloromethane (100 mL) was added the N-methyl morpholine (0.56 g, 5.6 mmol) and methyl chloroformate (0.37 mL, 4.8 mmol) at 0° C. The resulting solution was stirred for 10 minutes before the addition of a solution of 5(R,S)-amino-2,3,4,5-tetrahydro-3-methyl-2-(1-methylethyl)-1H-2,3-benzodiazepin-1,4-dione (IIIA, 1.0 g, 4.04 mmol) in dichloromethane (5 mL) and it was further stirred for another 1 h. The resulting mixture was washed with 1N hydrochloric acid (50 mL), sodium bicarbonate (50 mL), brine (50 mL) and dried over MgSO4, filtered and concentrated to afford the crude product. This product was purified further on flash (silica gel) chromatography (hexane/ethyl acetate, 3/2) to afford 2,3,4,5-tetrahydro-3-methyl-5(R,S)-[[(2S)-2-[(1,1-dimethylethoxycarbonyl)amino]-3-methyl-1-oxobutyl]amino]-2-(1-methylethyl)-1H-2,3-benzodiazepin-1,4-dione(1.5 g, 83%).

Provenance & Evidence