Triphosgene → 1-(1-tert-butylcarbonylmethyl-2-oxo-5-cyclohexyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-3-yl)-3-(3-tert-butoxycarbonyl-4-methylphenyl)urea

Participants

Reaction Steps

Under ice-cooling, triphosgene (205 mg) was added to a solution of tert-butyl 2-methyl-5-aminobenzoate (383 mg) in anhydrous tetrahydrofuran (40 ml), triethylamine (825 μl) was added thereto five times over 15 minutes after divided into five portions. After the mixture was stirred at room temperature for 5 minutes, a solution of 1-tert-butylcarbonylmethyl-2-oxo-3-amino-5-cyclohexyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepine (600 mg) in anhydrous tetrahydrofuran (10 ml) was added under ice-cooling. The resultant mixture was stirred at room temperature for one hour, the reaction mixture was poured into ice-water, extracted with ethyl acetate, and the organic layer was washed with saturated brine. After dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure, diisopropyl ether was added to the residue for crystallization, and collected by filtration, to thereby obtain 960 mg of the title compound (Yield: 97%).

Provenance & Evidence