Sulfuric Acid → Methyl 4-phenylpiperidine-4-carboxylate

Participants

Reaction Steps

To a solution of 4-phenyl-piperidine-4-carboxylic acid 4-toluene sulfonate (3.0 g, 0.008, mol) in methanol was added sulfuric acid (1.28 mL, 0.023 mol) and heated under reflux for 12 h. Excess methanol was evaporated and the residue poured into a cooled mixture of ice and 32% aqueous NaOH (if necessary adjust pH to >10). The aqueous phase was extracted with DCM, the combined organic phases were dried over Na2SO4 and the solvent was evaporated. The residue was evaporated several times with toluene and used crude for the next reaction.

Provenance & Evidence