Water → tert-butyl {1-[4-(2-bromo-9H-imidazo[1,2-d]pyrido[2,3-b][1,4]benzodiazepin-3-yl)phenyl]cyclobutyl}carbamate

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Reaction Steps

tert-Butyl {1-[4-(9H-imidazo[1,2-d]pyrido[2,3-b][1,4]benzodiazepin-3-yl)phenyl]cyclobutyl}carbamate (9.8 g, 20.4 mmol) was dissolved in THF (350 mL). A solution of pyridinium bromide perbromide (6.5 g, 20.4 mmol) in THF (50 mL) was added to the mixture at −78° C. After three hours stirring at r.t., pyridinium bromide perbromide (2.6 g, 8.2 mmol) in THF was added to the mixture and the mixture was stirred at rt overnight. The mixture was poured into ethyl acetate (1.5 L) and mixed with water and separated. The combined organic phase was washed with saturated sodium bicarbonate solution in water, then dried with anhydrous sodium sulfate and evaporated. The residue was purified with silica gel column chromatography (dichloromethane/ethyl acetate, 20:1) to give the titled compound as a white solid (6.8 g, 59%). 1HNMR (CDCl3) 400 MHz δ: 8.04 (d, J=8.0 Hz, 2H), 7.40 (d, J=7.4 Hz, 2H), 7.31 (t, J=7.4 Hz, 1H), 7.23 (d, J=6.9 Hz, 2H), 7.12 (t, J=7.7 Hz, 1H), 6.94 (d, J=8.0 Hz, 1H), 6.88-6.80 (m, 1H), 6.66-6.62 (m, 1H), 6.29 (s, 1H), 5.10 (s, 1H), 2.58-2.37 (m, 4H), 2.18-2.08 (m, 1H), 1.94-1.84 (m, 1H), 1.39 (br s, 9H); LC/MS [M+H]: 558

Provenance & Evidence