Diisopropylethylamine → {(S)-1-[(2S,3S)-1-(4-acetyl-benzoyl)-2-methyl-4-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-ylcarbamoyl]-ethyl}-methyl-carbamic acid tert-butyl ester

Participants

Reaction Steps

To a solution of (3S,4S)-5-(4-acetyl-benzoyl)-3-amino-4-methyl-1,3,4,5-tetrahydro-benzo[b][1,4]diazepin-2-one hydrochloride (0.39 g, 1.03 mmol) in N,N-dimethylformamide (6.0 mL) at 0° C. was added (S)-2-(tert-butoxycarbonyl-methyl-amino)-propionic acid (0.23 g, 1.13 mmol), N,N-diisopropylethylamine (0.72 mL, 4.12 mmol) and 0-benzotriazol-1-yl-N,N,N′N′-tetramethyluronium hexafluorophosphate (0.43 g, 1.13 mmol), the reaction was stirred for 2 h. The reaction mixture was diluted with water (50 ml) and extracted with ethyl acetate (2×40 mL). The organic layers were combined, washed with a saturated aqueous solution of sodium hydrogen carbonate (1×20 mL), water (1×25 mL), dried over sodium sulfate, filtered through a plug of silica gel and concentrated in vacuo to give {(S)-1-[(2S,3S)-1-(4-acetyl-benzoyl)-2-methyl-4-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-ylcarbamoyl]-ethyl}-methyl-carbamic acid tert-butyl ester which was used in the subsequent step without further purification (0.53 g, 98%).

Provenance & Evidence