Methanol → 1H-indole-6-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A solution of methyl indole-6-carboxylate (11.0 g) in a mixture of tetrahydrofuran (150 ml), methanol (150 ml), and water (63 ml) was treated with lithium hydroxide monohydrate (15.8 g). The mixture was stirred at 60° C. for 6 hours and then concentrated to remove the organic solvents. The residue was dissolved in water, and the solution was acidified with 50% (v/v) hydrochloric acid. The precipitate which formed was collected by filtration and dried to give indole-6-carboxylic acid (9.6 g, 95%) as a tan powder; mp 253°-254°: NMR (80 MHz; CDCl3) 6.51(m, 1H, H3 -indole), 8.04(m, 1H, H7 -indole), 11.43(broad s, 1H, NH), 12.42(broad s, 1H, OH).

Provenance & Evidence