Hydrochloric Acid → 1-Benzoyl-4-benzylpiperidine-4-carboxylic acid

Participants

Reaction Steps

To 10.7 g (26 mmoles) crude ethyl 1-benzoyl-4-(phenylmethyl)-4-piperidinecarboxylate was added a solution of 14.6 g (130 mmoles) potassium tert-butoxide in 130 ml dimethyl sulfoxide. The resulting purple solution was stirred 2 hours to give a dark orange solution. The solution was poured into 500 ml rapidly stirred ice-water and acidified with 12 ml concentrated hydrochloric acid. The resulting white precipitate was filtered off, washed with 3×20 ml cold water, then dissolved in 200 ml ether. The ether solution was washed with 3×20 ml water, and brine, dried, and the solvent was removed in vacuo to give a pale yellow foam. The product was recrystallized from ether to give 6.63 g (75%) product, m.p. 183°-189° C.

Provenance & Evidence