反应详情

To a solution of ethyl 4-bromo-3,5-dimethyl-1H-pyrrole-2-carboxylate (0.050 mL, 0.610 mmol) in THF (3 mL), was added NaH (36.6 mg, 0.914 mmol). The mixture was stirred for 10 min and then MeI (0.046 mL, 0.731 mmol) was added dropwise. The resulting mixture was stirred overnight. The reaction was quenched with sat. NH4Cl. The aqueous layer was extracted with EtOAc (3×). The combined organic layers were washed with brine (1×), dried (Na2SO4) and concentrated in vacuo. The residue was purified by flash chromatography (Biotage Horizon, 12M, Si, ˜10 mL/min, 100% hexanes for 36 mL, gradient to 20% EtOAc in hexanes over 1032 mL) to afford ethyl 4-bromo-1,3,5-trimethyl-1H-pyrrole-2-carboxylate. 1H NMR (500 MHz, CDCl3): δ 4.31 (q, J=7.1 Hz, 2H); 3.82 (s, 3H); 2.31 (s, 3H); 2.26 (s, 3H); 1.38 (t, J=7.1 Hz, 3H).

1. stirringThe resulting mixture was stirred overnight
2. customThe reaction was quenched with sat. NH4Cl
3. extractionThe aqueous layer was extracted with EtOAc (3×)
4. washThe combined organic layers were washed with brine (1×)
5. dry with materialdried (Na2SO4)
6. concentrationconcentrated in vacuo
7. customThe residue was purified by flash chromatography (Biotage Horizon, 12M, Si, ˜10 mL/min, 100% hexanes for 36 mL, gradient to 20% EtOAc in hexanes over 1032 mL)