Hydrochloric Acid → 3,3-dimethyl-2-oxo-2,3-dihydro-1H-indole-5-carboxylic acid

Participants

Reaction Steps

To a solution of sodium hydroxide (14 g) in water (480 ml) was added 1-[2-(2,3-dihydro-3,3-dimethyl-2-oxoindol-5-yl)-2-oxoethyl]pyridinium chloride (44.3 g) and the mixture was stirred for 1.5 hours at 80° to 85° C. After cooling, the reaction mixture was acidified with conc. hydrochloric acid. The residual crystal was collected by filtration, washed with water and dried to give 2,3-dihydro-3,3-dimethyl-2-oxoindole-5-carboxylic acid (21 g).

Provenance & Evidence