Triethylamine → 5-(4-bromo-2-chlorophenyl)-7-(cyclopropylsulfonyl)-4-fluoro-5H-imidazo[4',5':4,5]benzo[1, 2-d]oxazol-6(7H)-one

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Reaction Steps

To a solution of 5-(4-bromo-2-chlorophenyl)-4-fluoro-5H-imidazo[4′,5′:4,5]benzo[1,2-d]oxazol-6(7H)-one (100 mg, 0.26 mmol) in CH2Cl2 (10 mL) was added triethylamine (80 mg, 0.78 mmol) at 0° C. followed by cyclopropanesulfonyl chloride (55 mg, 0.39 mmol) and DMAP (10 mg). The mixture was stirred at room temperature for 1 h and washed with saturated NaHCO3 (aq.). The aqueous layer was extracted with CH2Cl2 (15 mL×2). The combined organic phase was washed with water (15 mL) and brine (20 mL) successively, dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (petroleum ether/ethyl acetate, 5:1, v/v) to give the corresponding product (110 mg, 86.5% yield). 1H NMR (400 MHz, CDCl3): δ 8.09 (s, 1H), 7.99 (s, 1H), 7.71-7.69 (m, 2H), 7.32 (m, 1H), 3.35 (m, 1H), 1.69 (m, 2H), 0.88 (m, 2H).

Provenance & Evidence