反应详情

2-bromo-4-(5-chloro-2-methoxyphenyl)thiazole-5-carboxylic acid (1.22 g, 3.50 mmol), diphenylphosphoryl azide (963 mg, 3.50 mmol) and triethylamine (354 mg, 3.50 mmol) in tert-butanol (30 mL) were stirred at 85° C. for 4 hours. After cooling, the reaction was partitioned between ethyl acetate and water, the organics separated then washed with brine, and evaporated to dryness. The resulting residues were purified by flash chromatography on silica gel (50 to 100% dichloromethane in cyclohexane) to yield tert-butyl 2-bromo-4-(5-chloro-2-methoxyphenyl)thiazol-5-ylcarbamate (970 mg, 66%). LCMS (method 1) [M+H-tBu]+=364.8, RT=4.61 min. 1H NMR (400 MHz, DMSO-d6): δ (ppm) 7.43 (dd, 1H), 7.30 (d, 1H), 7.11 (d, 1H), 3.77 (s, 3H), 1.45 (s, 9H).

1. temperatureAfter cooling
2. customthe reaction was partitioned between ethyl acetate and water
3. customthe organics separated
4. washthen washed with brine
5. customevaporated to dryness
6. customThe resulting residues were purified by flash chromatography on silica gel (50 to 100% dichloromethane in cyclohexane)