Tetrahydrofuran → 5-(2-methoxyethoxy)-7-[(pyridin-2-ylsulfonyl)amino]-1H-indole-2-carboxylic acid

Participants

Reaction Steps

To a mixture of ethyl 5-(2-methoxyethoxy)-7-[(pyridin-2-ylsulfonyl)amino]-1H-indole-2-carboxylate (5.40 g), tetrahydrofuran (50 mL) and methanol (50 mL) was added a 85% aqueous solution (30 mL) of potassium hydroxide (3.0 g), and the mixture was stirred at room temperature for 15 hr. The reaction mixture was concentrated, aqueous citric acid solution was added to the residue, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with water, and concentrated to give a white solid. The obtained solid was washed with a mixed solvent of ethyl acetate-hexane to give the title compound (4.24 g, yield 84%) as colorless crystals. melting point 230-232° C.

Provenance & Evidence