Triethylamine → 3-Cyano-4-methyl-2-(2-oxopyrrolidin-1-yl)-5-phenylpyrrole

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-cyano-4-methyl-2-amino-5-phenylpyrrole (4.9 g) in THF (80 ml) was added triethylamine (2.5 g) and while the mixture was stirred at −50° C., 4-chlorobutyryl chloride (3.5 g) was added. This reaction mixture was then stirred at room temperature for 1.5 hours, after which the insoluble matter was filtered off. The filtrate was diluted with ethyl acetate and the organic layer was washed with water and saturated aqueous solution of sodium hydrogen carbonate, dried over MgSO4, and concentrated under reduced pressure. The residue was recrystallized from benzene/n-hexane. The crystals were suspended in ethanol (40 ml), and potassium tert-butoxide (1.32 g) was added thereto. The mixture was stirred at room temperature overnight and the resulting crystals were collected by filtration, washed with water, and air-dried. The crude crystals thus obtained were recrystallized from ethanol to provide the title compound as light-yellow needles (1.5 g). m.p. 140-141° C.

Provenance & Evidence