4-Methylmorpholine → 2-Oxo-(3S)-3-tert-butoxycarbonylamino-2,3,4,5-tetrahydro-7,9-dimethyl-1H-1,5-benzodiazepine

Participants

Reaction Conditions

Reaction Steps

A 0° C. solution of (2S)-2-tert-butoxycarbonylamino-3-(2-amino-3,5-dimethylphenyl-amino)-propionic acid (763 mg, 2.36 mmol) and N-methylmorpholine (483 mg, 4.78 mmol) in 60 ml of anhydrous THF was treated dropwise with isobutylchloroformate (352 mg, 2.5 mmol). The reaction was stirred for 2 h at 0° C., at RT for 1 h and poured over EtOAc. The mixture was washed with aq. 5% NaHSO4, sat. aq. NaHCO3, and sat. aq. NaCl, dried over NaSO4, and concentrated in vacuo. Chromatography (flash, SiO2, 10% to 25% to 50% EtOAc/CH2Cl2) gave 490 mg (68%) of the desired product.

Provenance & Evidence