Potassium Hydroxide → 1-Piperidin-4-yl-2,3-dihydro-1H-indole

Participants

Reaction Steps

A mixture of intermediate 6 (95 g) and potassium hydroxide (194 g) in 2-propanol (1300 ml) was stirred and refluxed for 24 hours. The solvent was evaporated and the residue was dissolved in H2O/CH2Cl2. The organic layer was separated, dried over MgSO4, filtered and evaporated, yielding 64 g (90.4%) of 2,3-dihydro-1-(4-piperidinyl)-1H-indole. A sample (4.5 g) was crystallized from CH3OH and converted into the hydrochloric acid salt (1:1) in 2-propanol and filtered off, yielding 3.0 g of 2,3-dihydro-1-(4-piperidinyl)-1H-indole monohydrochloride (intermediate 7).

Provenance & Evidence