Ethyl 1,4-dimethyl-1H-pyrrole-2-acetate → ethyl 5-(4-chlorobenzoyl)-1,4-dimethyl-1H-pyrrole-2-acetate

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Reaction Steps

A 1.50 g (0.0090 mole) sample of 4-chlorobenzoylcyanide was added over a one-hour period to 1.50 g (0.0082 mole) of ethyl 1,4-dimethylpyrrole-2-acetate at 120°-130° through which nitrogen was slowly bubbled. The mixture was heated for 27 hours. The resulting oil was chromatographed on silica gel with successive elution with hexane and 1,1,1-trichloroethane. The solvent was evaporated in vacuo from compound-bearing fractions. The residue was chromatographed through a Waters Associates, Prep LC, System 500 with elution with a 2:3 mixture of hexane:1,1,1-trichloroethane. Evaporation of solvent from the second compound-bearing fraction afforded solid which was recrystallized from methanol to give 0.74 g (28 percent yield) of ethyl 5-(4-chlorobenzoyl)-1,4-dimethylpyrrole-2-acetate, mp 108°-109°, undepressed by admixture with authentic material.

Provenance & Evidence