Hydrochloric Acid → 5-chloro-2-oxo-3-(thiophene-2-carbonyl)-3H-indole-1-carboxamide

Participants

Reaction Steps

A stirred slurry of 21.1 g (0.1 mole) of 5-chloro-2-oxindole-1-carboxamide and 26.9 g (0.22 mole) of 4-(N,N-dimethylamino)pyridine in 200 ml of N,N-dimethylformamide was cooled to ice-bath temperature, and then a solution of 16.1 g (0.11 mole) of 2-thenoyl chloride in 50 ml of N,N-dimethylformamide was added dropwise. Stirring was continued for ca. 30 minutes, and then the reaction mixture was poured into a mixture of 1 liter of water and 75 ml of 3N hydrochloric acid. The resulting mixture was cooled in an ice-bath, and then the solid was collected by filtration. The solid was washed with water and then recrystallized from 1800 ml of acetic acid, to give 26.6 g of the title compound as fluffy, yellow crystals, m.p. 230° C. (dec.).

Provenance & Evidence