p-Toluenesulfonic acid → 1-(2-Chlorophenyl)-3-methyl-5-piperidin-1-yl-1,5,6,7-tetrahydropyrrolo[3,2-c]pyridine-4-one

Participants

Reaction Steps

To a solution of [1,1′]bipiperidinyl-2,4-dione, from Step 4 (2.49 g, 12.7 mmol) in dry toluene (240 ml) at room temperature were added 1-(2-chlorophenylamino)propan-2-one (2.33 mg, 12.7 mmol) from Step 5 followed by a catalytic amount of p-TSA. The reaction mixture was boiled under reflux with a Dean-Stark trap, and 90 ml toluene was collected in the trap. Then 1 molar equivalent of p-TSA was added and the reaction mixture was boiled under reflux overnight. After cooling to room temperature, the reaction mixture was evaporated and purified by flash chromatography (heptane:EtOAc gradient) to give 0.93 g (21%) of the title compound.

Provenance & Evidence