Dimethylformamide → HCID 15766627, compound

Participants

Reaction Conditions

Reaction Steps

Chlorosulfonyl isocyanate (8.1 g, 0.0572 mol) is added dropwise to a 50° C. stirred mixture of 5-(p-chlorophenyl)-1-methoxypyrrole-3-carboxylic acid (6.0 g, 0.0238 mol) in acetronitrile and dimethylformamide. The reaction mixture is stirred at room temperature for 20 hours, cooled to 0° C., treated with dimethylformamide (9.2 mL), heated to 50° C. for 1 hour, cooled to room temperature for 3 hours, diluted with water and extracted with chloroform. The combined chloroform extracts are washed sequentially with water, saturated sodium bicarbonate solution, water and brine, dried over anhydrous sodium sulfate and concentrated in vacuo to give a gum. The gum is chromatographed using silica gel, and methylene chloride as eluent to give 2 products as a mixture. Crystallization from chloroform gives 2-(p-chlorophenyl)-1-methoxypyrrole-3,4-dicarbonitrile (1.1 g, 18%), as a yellow solid, mp 193°-194° C. The filtrate from the above crystallization is chromatographed using silica gel, and 30% ethyl acetate in heptane as eluent to give the title compound as a yellow solid (0.93 g, 15%), mp 126°-127° C.

Provenance & Evidence