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

Participants

Reaction Conditions

Reaction Steps

A slurry of N-[(p-chlorophenyl)cyanomethyl]-2,2,2-trifluoroacetamide (13.1 g, 0.05 mol) in toluene is treated sequentially with methanesulfonic acid (2.4 g, 0.025 mol) and acetyl chloride (4.32 g, 0.055 mol), at room temperature, heated at 80° C. for 2 hours, cooled to room temperature, diluted with acetonitrile, treated first with 2-chloroacrylonitrile (5.25 g, 0.06 mol) then dropwise with triethylamine (13.7 g, 0.135 mol), heated at 70°-72° C. for 1 hour, cooled to room temperature and diluted with water. The mixture is extracted with ethyl acetate. The extracts are combined, washed with water and concentrated in vacuo to give a residue. Flash chromatography (silica-gel; 15% ethyl acetate in heptane as eluent) to give the title product.

Provenance & Evidence