反应详情

A yellow slurry consisting of ethyl 2-bromo-2-(2-naphthyl)acetate (384.04 grams, 1.31 mol), 4-nitroimidazole (148.13 grams, 1.31 mol), potassium carbonate (362.11 grams, 2.62 mol), and dimethyl formamide (2500 mL) was stirred at ambient temperature until complete as determined by hplc (16 hours). The reaction mixture was diluted with water (2000 mL) and extracted with ethyl acetate (4×500 mL). The organic extracts were combined and washed with saturated sodium bicarbonate solution (2×500 mL), 10% citric acid solution (2×500 mL), saturated sodium chloride solution (2×500 mL), dried using sodium sulfate, and evaporated. A portion (50 grams) of the crude product was purified by column chromatography on silica gel eluting with dichloromethane:heptane (16:3) gradient to dichloromethane:heptane:methanol (16:3:0.2) giving 30.99 grams of ethyl 2-(2-naphthyl)-2-(4-nitroimidazolyl)acetate which was 90% pure by hplc. A 1 gram sample of the product was purified a second time using a Biotage Flash 40S system eluting with dichloromethane:heptane:methanol (16.9:3:0.1) to give 0.90 grams (46%) of ethyl 2-(2-naphthyl)-2-(4-nitroimidazolyl)acetate as a tan oil. MS (FIA) m/z 326.4 [(M+H)+]. 1H nmr (CDCl3): δ 1.25-1.31 (t, 3H), 4.28-4.39 (m, 2H), 6.16 (s, 1H), 7.36-7.44 (dd, 1H), 7.54-7.62 (m, 3H), 7.84-7.90 (m, 3H), 7.90-7.95 (m, 2H).

1. customas determined by hplc (16 hours)
2. extractionextracted with ethyl acetate (4×500 mL)
3. washwashed with saturated sodium bicarbonate solution (2×500 mL), 10% citric acid solution (2×500 mL), saturated sodium chloride solution (2×500 mL)
4. customdried
5. customevaporated
6. customA portion (50 grams) of the crude product was purified by column chromatography on silica gel eluting with dichloromethane:heptane (16:3) gradient to dichloromethane:heptane:methanol (16:3:0.2)