Phenylhydrazine → 1H-Indole, 2-(2-benzofuranyl)-

Participants

Reaction Conditions

Reaction Steps

Phenylhydrazine (97%; 6.3 ml, 1 eq) is introduced into a solution of 2-acetylbenzofuran (10 g, 1 eq) in ethanol (25 ml). After adding 20 drops of glacial acetic acid, the mixture is stirred at 80° C. for 1 h. Subsequently, the solvent is distilled off. The residue is introduced gradually into polyphosphoric acid (100 g), heated to 120° C. and stirred for 1 h. The reaction output is added cautiously to ice-water and neutralized with 2M NaOH. The precipitate is filtered off and washed with distilled water. The residue is dried under reduced pressure. After recrystallization in ethyl acetate/n-hexane, 7.0 g are obtained. Yield: 48%

Provenance & Evidence