反应详情

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.

1. customwas slowly bubbled
2. temperatureThe mixture was heated for 27 hours
3. customThe resulting oil was chromatographed on silica gel with successive elution with hexane and 1,1,1-trichloroethane
4. customThe solvent was evaporated in vacuo from compound-bearing fractions
5. customThe residue was chromatographed through a Waters Associates, Prep LC, System 500 with elution with a 2:3 mixture of hexane
6. customEvaporation of solvent from the second compound-bearing fraction
7. customafforded solid which
8. customwas recrystallized from methanol