Hydrochloric Acid → 1-Methyl-5-(p-toluoyl)pyrrole-2-acetonitrile

Participants

Reaction Steps

A solution of 0.16 g (1.1 mmole) of 4-methylbenzoylcyanide, 0.13 g (1.1 mmole) of 1-methylpyrrole-2-acetonitrile and 4 mg of trichloroacetic acid in 0.4 ml of ether was allowed to stand in the dark under nitrogen at 25°. After three days, a small amount of hydrogen chloride gas was admitted to the vessel. The mixture was allowed to stand for 14 days. It was diluted with methylene chloride and the solution washed with sodium hydroxide. The solution was dried (MgSO4) and the solvent evaporated in vacuo. The residue was chromatographed on 37 ml of silica gel. The fractions eluted with a mixture of 1,1,1-trichloroethane:hexane, 1:1 were discarded. The fractions eluted with 1,1,1-trichloroethaneihexane 3:1 were collected. The solvent was evaporated to give 0.80 g of dark solid 1-methyl-5-(4-methylbenzoyl)pyrrole-2-acetonitrile (30 percent yield). It was recrystallized from 1,1,1-trichloroethaneihexane to give brown solid, mp 103°-104°, undepressed by admixture with authentic material.

Provenance & Evidence