Hydrochloric Acid → HCID 12764254, compound

Participants

Reaction Steps

To a solution of 2,3-dihydro-5-methoxy-1-(2-methyl-1-oxo-2-propenyl)-1H-indole-2-carboxylic acid ethyl ester from Example 23 (8.5 g.) in 45 ml. of reagent-grade methanol was added a solution of 1.32 g. of sodium hydroxide (98% purity) in 16 ml. distilled water with hand swirling. This reaction mixture was stirred at room temperature for 2 hours. With vigorous mechanical stirring, the reaction solution was poured into brine and the slightly turbid mass was acidified with concentrated hydrochloric acid. The resulting mixture was stirred, chilled in an ice-water-salt-bath for one hour and the solids were collected on a sintered-glass funnel and washed twice with cold water, to give 2,3-dihydro-5-methoxy-1-(2-methyl-1-oxo-2-propenyl)-1H-indole-2-carboxylic acid (7.32 g., m.p. 108°-111°). Recrystallization from ethyl acetate improved the m.p. to 115°-118°.

Provenance & Evidence