Ethyl chloroformate → Ethyl 4-(4-chlorophenyl)-5-(2,4-dichlorophenyl)-1-methylimidazole-2-carboxylate

Participants

Reaction Steps

To a solution of 4-(4-chlorophenyl)-5-(2,4-dichlorophenyl)-1-methylimidazole (100 mg, 0.30 mmol) from Step C in THF (4 mL) cooled to −70° C. in a dry ice/acetone bath was added 1.6N n-butyl lithium in hexanes (0.22 mL, 0.36 mmol). The reaction was stirred for 1 hr and then ethyl chloroformate (0.060 mL, 60 mmol) was added via syringe. The reaction was allowed to warm to rt for 1 hr and was then quenched with aq. sodium bicarbonate and extracted twice with ethyl acetate. The organic layers were washed with brine, dried over sodium sulfate, and evaporated. The residue was purified by Prep TLC (2×1 mm, silica) (25% ethyl acetate in hexanes) to afford the title compound.

Provenance & Evidence