Diisopropylethylamine → tert-Butyl methyl((S)-1-oxo-1-((S)-4-oxo-2,3,4,5-tetrahydrobenzo[b][1,4]oxazepin-3-ylamino)propan-2-yl)carbamate

Participants

Reaction Steps

To a mixture of (S)-3-amino-2,3-dihydrobenzo[b][1,4]oxazepin-4(5H)-one trifluoroacetate (500 mg, 1.71 mmol, Eq: 1.00), (S)-2-(tert-butoxycarbonyl(methyl)amino)propanoic acid (348 mg, 1.71 mmol, Eq: 1.00), O-benzotriazol-1-yl-N,N,N′N′-tetramethyluronium hexafluorophosphate (HBTU, 682 mg, 1.8 mmol, Eq: 1.05) and 1-hydroxybenzotriazole hydrate (HOBT120, 243 mg, 1.8 mmol, Eq: 1.05) in DMF (5 mL) was added N,N-diisopropylethylamine (DIEA, 553 mg, 4.28 mmol, Eq: 2.50). The mixture was stirred for 45 min., diluted with 50 mL EtOAc and washed H2O, 2% KHSO4, 5% NaHCO3 and 5% brine. The organic solution was dried over Na2SO4, filtered and concentrated to give the title compound (525 mg, 84%) as a tan foam which was used without purification.

Provenance & Evidence