Ethyl Acetate → (3S)-2-Oxo-3-tert-butoxycarbonylamino-2,3,4,5-tetrahydro-1H-1,5-benzodiazepine-1-acetic acid methyl ester

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Reaction Steps

(3S)-2-Oxo-3-tert-Butoxycarbonylamino-1,3,4,5-tetrahydro-1H-1,5-benzodiazepine. 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (8.54 g, 44.5 mmol) was added to a cooled (0° C.) solution of (2S)-2-tert-butoxycarbonylamino-3-(2-aminophenylamino)propionic acid (11.95 g, 40.5 mmol) in 100 ml of DMF and stirred for 18 h. The reaction was poured into 700 ml of EtOAc and washed four times with 100 ml of H2O. The organic layer was dried over anhydrous Na2SO4, filtered, and evaporated to give a brown solid that was purified by flash chromatography eluting with 3:7 EtOAc/hexane to give 8 g (71%) of the title compound: 1H NMR (CDCl3) δ 7.78 (1H, s), 7.02-6.95 (1H, m), 6.88-6.82 (1H, m), 6.82-6.78 (1H, m), 6.75-6.70 (1H, m), 5.8-5.7 (1H, d), 4.55-4.45 (1H, m), 3.95 (1H, s), 3.9-3.82 (1H, m), 3.48-3.40 (1H, m), 1.45 (9H, s).

Provenance & Evidence