Toluene → 1-(2,3-Dihydro-1H-inden-1-yl)piperidine

Participants

Reaction Steps

A mixture of 100 g. of 1-indanone (0.758 mole) and 125 ml. of piperidine in 750 ml. of toluene is treated with 0.5 g. of p-toluenesulfonic acid and heated under reflux with a water take-off trap attached. Heating is continued for 48 hours. Solvent and excess piperidine are removed in vacuo and the residue is dissolved in 1500 ml. of absolute methanol. The resulting solution is stirred and treated portionwise with 50 g. of sodium borohydride below 30° C. After stirring several hours longer, the mixture is treated with a small amount of acetic acid then made strongly basic by the addition of sodium hydroxide solution. After 400 ml. of water is added, most of the methanol is removed in vacuo. Product is extracted into ether, dried over potassium hydroxide and distilled. 119.7 g. of 1-(1-indanyl)piperidine is collected at 101°-102° (0.2 mm.).

Provenance & Evidence