4-(2,4-dichlorophenyl)-1H-pyrrole-3-carbonitrile

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1.2 ml of chloral and 1.8 ml of triethylamine are added dropwise in succession to 2.4 g of 3-(2,4-dichlorophenyl)-4-cyanopyrrole in 50 ml of tetrahydrofuran. The reaction mixture is stirred for 11/2 hours at 25° C., then 0.1 g of 4-dimethylaminopyridine is added and the mixture is cooled to -10° C. A solution of 0.9 ml of acetyl chloride in 10 ml of tetrahydrofuran is added very slowly dropwise at -10° to -5° C. and the reaction mixture is subsequently stirred for 30 minutes at 0° C. and then for 1 hour at room temperature, and filtered. The filtrate is concentrated and the residue is dissolved in diethyl ether. The ethereal solution is washed twice with a semi-saturated solution of sodium chloride, dried over sodium sulfate, and filtered. The filtrate is concentrated and the crude product is recrystallised from diethyl ether/petroleum ether to give colourless crystals of the title compound with a melting point of 111°-113° C. the mixture is cooled to -10° C the reaction mixture is subsequently stirred for 30 minutes at 0° C. for 1 hour at room temperature filtered The filtrate is concentrated the residue is dissolved in diethyl ether The ethereal solution is washed twice with a semi-saturated solution of sodium chloride dried over sodium sulfate filtered The filtrate is concentrated the crude product is recrystallised from diethyl ether/petroleum ether