Acetic Anhydride → 2-(4-chlorophenyl)-1-methyl-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-(p-chlorophenyl)-N-(trifluoroacetyl)sarcosine (147.7 g, 0.50 mol) in acetonitrile is treated dropwise with α-chloroacrylonitrile (54.7 g, 0.62 mol) and acetic anhydride (153 g, 1.5 mol), stirred vigorously, treated dropwise with triethylamine (58.1 g, 0.57 mol) at 56°-60° C. over a 11/4 hour period, heated at 60° C. for 16 hours and concentrated in vacuo to give a residue. The residue is partitioned between ethyl acetate and water. The organic phase is concentrated in vacuo to afford an amber solid residue. Said solid is purified by flash chromatography (silica; ethyl acetate/hexanes) and recrystallized from methanol to give the title product as a pale yellow solid, mp 129.5°-130.5° C.

Provenance & Evidence