Acrylonitrile → 2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile

Participants

Reaction Conditions

Reaction Steps

A solution of N-[1-chloro-(2,2,2-trifluoroethyl)]-4-chlorobenzimidoyl chloride (5.80 g, 0.02 mol) and acrylonitrile (1.33 g, 0.025 mol) in N,N-dimethyl-formamide (15 mL) is treated with 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU, 8.53 g, 0.056 mol) over 1 hour while maintaining the temperature at 45°-50° C. The reaction mixture is then stirred at 50° C. for 4 hours, quenched with dilute HCl, and extracted with ethyl acetate. The organic extract is concentrated in vacuo to obtain a residue. Flash chromatography of the residue on silica gel, packed and eluted with 20% ethyl acetate in heptane, and crystallization from heptane and small amount of ethyl acetate gives the title product as a white crystalline solid (2.1 g, 38.9% yield): mp 239-240° C. (dec).

Provenance & Evidence