4-Nitrophenyl chloroformate → HCID 86597452, compound

Participants

Reaction Steps

A solution of 50 mg (0.16 mmol) of (S)—N—((S)-5-acetyl-1-methyl-2-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-yl)-2-hydroxy-propionamide in 1.5 ml of pyridine was treated with 39 mg (0.18 mmol) of 4-nitrophenyl chloroformate, and the mixture was stirred at room temperature for 18 h. For the working-up, the solvent was evaporated and the residue chromatographed on silica gel using a 3:1-mixture of heptane and ethyl acetate as the eluent. There were obtained 31 mg (40% of theory) of carbonic acid (S)-1-((S)-5-acetyl-1-methyl-2-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-ylcarbamoyl)-ethyl ester 4-nitro-phenyl ester; MS: m/e=488 (M+NH4)+. The ester was treated with 0.7 ml of 2,2,3,3,3-pentafluoro-propylamine and the mixture was stirred at room temperature for 36 h. For the working-up, 3 ml of ethyl acetate were added and the solution was washed with a saturated solution of sodium carbonate and a saturated solution of sodium chloride. The organic layer was dried over sodium sulphate and evaporated under reduced pressure. For purification, the crude product was chromatographed on silica gel using a gradient of a 98:2- to 95:5-mixture of dichloromethane and methanol as the eluent. There were obtained 12 mg (38% of theory) of the title compound as a white solid; MS: m/e=498 (M+NH4)+.

Provenance & Evidence