Tetrahydrofuran → 6-chloro-7-[(2-thienylsulfonyl)amino]-1H-indole-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of ethyl 6-chloro-7-[(2-thienylsulfonyl)amino]-1H-indole-2-carboxylate (1.00 g), 4N aqueous sodium hydroxide solution (2.3 ml), tetrahydrofuran (5 ml) and methanol (5 ml) was stirred at 50° C. for 2 hr. The reaction mixture was concentrated, and acidified with 10% aqueous citric acid solution, and the resulting crystals were collected by filtration, washed with water, and dried to give the title compound (0.88 g, yield 95%) as colorless crystals. melting point >290° C. (decomposition).

Provenance & Evidence