反应详情

To a solution of ethyl 4-bromo-5-cyano-1H-pyrrole-2-carboxylate (2.70 g, 11.1 mmol) in DMF (75 mL) was added 95% sodium hydride powder (323 mg, 12.8 mmol). The mixture was stirred (rt) for 20 min, then (aminooxy)(diphenyl)phosphine oxide (3.89 g, 16.7 mmol) was added in one portion. After 15 min, the reaction mixture became thick and additional DMF (25 mL) was added. The reaction was heated (50° C.) for 3 h and was allowed to cool to rt and stir for 17 h. The reaction was poured into saturated aqueous NaHCO3 solution (200 mL) and was extracted with ethyl acetate (3×100 mL). The combined organics were washed with water (2×100 mL), dried (Na2SO4) and were concentrated to dryness to afford 2.8 g (100%) of the desired product, which contained minor impurities. 1H NMR (300 MHz, DMSO-d6) δ 6.95 (s, 1 H), 6.57 (s, 2 H), 4.28 (q, 2 H), 1.29 (t, 3 H).

1. waitAfter 15 min
2. temperatureThe reaction was heated (50° C.) for 3 h
3. temperatureto cool to rt
4. stirringstir for 17 h
5. extractionwas extracted with ethyl acetate (3×100 mL)
6. washThe combined organics were washed with water (2×100 mL)
7. dry with materialdried (Na2SO4)
8. concentrationwere concentrated to dryness