Indole → 3-(1,2,3,6-Tetrahydropyridin-4-yl)-1H-indole

Participants

Reaction Steps

Alternately, for example in step a, an appropriate indole of formula (1) is condensed with an appropriate piperid-4-one of formula (2) to give a 3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole of formula (3). The reaction may carried out in the presence of a suitable acid, typically phosphoric acid or sulfuric acid. The reaction is carried out in a suitable solvent, such as acetic acid and water. Typically, about 2-6 molar equivalents of the piperid-4-one of formula (2) are used. The reaction is generally carried out at temperatures of about 40° C. to 100° C. The reaction typically requires 8-72 hours. In general, the acidic conditions are favored for the condensation above compounds of formula (1) having a 5-hydroxy. The product can be isolated and purified by techniques well known in the art, such as precipitation, filtration, extraction, evaporation, trituration, chromatography, and recrystallization.

Provenance & Evidence