Methanesulfonic Acid → 2-(4-chlorophenyl)-1-methyl-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile

Participants

Reaction Conditions

Reaction Steps

A solution of N-(p-chloro-α-cyanobenzyl)-2,2,2-trifluoro-N-methylacetamide (13.8 g, 0.05 mol) in toluene is treated with 2-chloroacrylonitrile (4.4 g, 0.05 mol) and methanesulfonic acid (4.8 g, 0.05 mol), heated at 110° C. for 4 hours, treated with a second portion of 2-chloroacrylonitrile (4.4 g, 0.05 mol) and methanesulfonic acid (4.8 g, 0.05 mol), heated at 110° C. for 12 hours, cooled and treated with ethyl acetate and water. The phases are separated and the organic phase is washed with water and concentrated to give a residue. The residue is chromatographed using silica gel packed with 15% ethyl acetate in heptane and eluted with 20% ethyl acetate in heptane to give the title product as pale yellow crystals, 4.8 g (34% yield), mp 129°-130° C.

Provenance & Evidence