Sodium Hydroxide → ethyl 4-bromo-3-chloro-5-methyl-1H-pyrrole-2-carboxylate

Participants

Reaction Steps

Ethyl 4-bromo-5-methyl-1H-pyrrole-2-carboxylate (Intermediate 187, 2.87 g, 12.4 mmol) was dissolved in dry DMF (30 ml), N-chlorosuccinimide (1.66 g, 12.4 mmol) was added and resulting mixture was stirred at room temperature over night, more N-chlorosuccinimide (0.83 g, 6.2 mmol) was added and the reaction temperature was increased to 35° C., stirred for 4 hours. The mixture was poured into cold sodium hydroxide aqueous solution (2M) (50 ml), extracted with diethyl ether (2×50 ml). The organic phase was then washed with water (20 ml) and brine (20 ml), dried over anhydrous sodium sulfate and purified by column chromatography(hexanes/ethyl acetate, gradient) to give the desired product as a white crystal. (1.2 g).

Provenance & Evidence