Potassium Hydroxide → 6-fluoro-3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole

Participants

Reaction Steps

Powdered potassium hydroxide (144.4 g) was added carefully to a mechanically stirred mixture of 6-fluoroindole (49.23 g, 0.364 mol) and 4-piperidone monohydrate (111.93 g, 0.728 mol) in methanol (1500 ml). The mixture was then heated under reflux under nitrogen for 18 hr and then more potassium hydroxide (40 g) was added and the reaction mixture heated under reflux for a further 4 hr. The reaction mixture was allowed to cool to room temperature and poured onto ice-water (3 l) and stirred for 1 hr and the precipitated solid isolated by filtration and dried at 50° C. in vacuo to give a solid. (WO 9747302).

Provenance & Evidence