反应详情

Aluminum chloride (0.710 g, 5.33 mmol, 2.2 equiv) is added in one portion to a solution of methyl pyrrole-2-carboxylate (0.30 g, 2.42 mmol) in dry dichloroethane (12 mL) under N2 at rt. Subsequently, 2-chloro-2-methylpropane (0.26 mL, 2.42 mmol, 1.0 equiv) is added in one portion via syringe. After 2 h, the orange solution is quenched by slowly pouring into a saturated sodium bicarbonate solution. The resulting white suspension is extracted with diethyl ether (2×). The combined organic layers are dried (Na2SO4) and concentrated in vacuo to give 0.40 g of methyl 5-t-butylpyrrole-2-carboxylate as an off-white solid. Flash chromatography (40% hexane in dichloromethane) gives 0.3 6 g of the desired material as a white amorphous solid (81%). 1H NMR (CDCl3) d 8.82 (br s, 1H), 6.81 (t, 1H, J=3.3 Hz), 6.00 (t, 1H, J=3.3 Hz), 3.83 (s, 3H), 1.31 (s, 9H).

1. customthe orange solution is quenched
2. additionby slowly pouring into a saturated sodium bicarbonate solution
3. extractionThe resulting white suspension is extracted with diethyl ether (2×)
4. dry with materialThe combined organic layers are dried (Na2SO4)
5. concentrationconcentrated in vacuo