HCID 18407068, compound → HCID 18407060, compound

Participants

Reaction Steps

A solution of 1-(tert-butoxycarbonyl)-4-[(2-bromophenyl)methylene]-piperidine (XI, 8 g, 22.7 mmole) in ethyl acetate (75 ml) and ethanol (75 ml) was shaken with PtO2 (0.75 g) and hydrogen (60 psi) for 15 min. Two further batches of 1-(tert-butoxycarbonyl)-4-[(2-bromophenyl)-methylene]-piperidine (8 g each, 24 g total) were similarly reduced and the mixtures were filtered. The filtrates were combined and concentrated in vacuo. The residue (X) was dissolved in dioxane (200 ml) and 3N HCl (100 ml) and stirred for 18 hr. The solution was concentrated in vacuo and the residue was made basic with 50% sodium hydroxide. The mixture was extracted with CH2Cl2. The extracts were dried over Na2SO4 and concentrated in vacuo to give a yellow oil that was purified by short path vacuum distillation to give 4-(2-bromobenzyl)piperidine (VI) as a oil (15 g, 86.6%). The oil converted to the fumarate salt using fumaric acid (6.85 g) in 2-propanol to give 4-(2-bromobenzyl)piperidine fumarate as a white solid (15.8 g, 62.6% overall, mp: 164-165° C.).

Provenance & Evidence