Hydrochloric Acid → 1H-Indole-2-carboxylic acid, 4,5,6,7-tetrahydro-3-hydroxy-, ethyl ester

Participants

Reaction Steps

294 g of 2-(ethoxycarbonylmethylamino)-cyclohexene-1-carboxylic acid ethyl ester in 400 ml of ethanol are added dropwise, under nitrogen, to a well-stirred solution of 35 g of sodium in 1.5 liters of ethanol. After the solution has boiled for three hours, it is cooled and 600 ml of water are then added, followed by 150 ml of concentrated hydrochloric acid. After the batch has stood for six hours at -10° C., 142 g of 3-hydroxy-4,5,6,7-tetrahydroindole-2-carboxylic acid ethyl ester, of melting point 94°-95° C., are filtered off.

Provenance & Evidence