Diisopropylethylamine → tert-butyl(S)-1-((2S,3S)-8-cyano-2-methyl-1-(2-(methylsulfonyl)acetyl)-4-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-ylamino)-1-oxopropan-2-yl(methyl)carbamate

Participants

Reaction Steps

A rt solution of tert-butyl(2S,3S)-8-cyano-2-methyl-1-(2-(methylsulfonyl)acetyl)-4-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-ylcarbamate (137 mg, 314 μmol) in 4 M HCl in dioxane (1.57 ml) was stirred for 2 h. The reaction was concentrated, taken up in in DMF (1.05 ml), and Boc-N-methyl-L-alanine (70.2 mg, 345 μmol), N,N-diisopropylethylamine (217 μl, 1.26 mmol), and HBTU (131 mg, 345 μmol) were added at 0° C. The reaction was stirred at rt for 30 min, then diluted with EtOAc, washed with H2O, sat. aq. NaHCO3, and sat. aq. NaCl, dried over Na2SO4, filtered, and concentrated. The crude material was purified by flash chromatography to provide tert-butyl(S)-1-((2S,3S)-8-cyano-2-methyl-1-(2-(methylsulfonyl)acetyl)-4-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-ylamino)-1-oxopropan-2-yl(methyl)carbamate (121.8 mg, 74%) as a white solid. MS m/z 544 (MNa)+.

Provenance & Evidence