Trifluoroacetic acid → 4-(3-Fluorophenoxy)piperidine

Participants

Reaction Steps

A solution of 1,1-dimethylethyl 4-[(3-fluorophenyl)oxy]-1-piperidinecarboxylate (D11) (16.4 g, 55 mmol) in DCM (200 ml) at 0° C. was treated with TFA (17 ml). The reaction was warmed to room temperature and stirred overnight. The solvent was then removed in vacuo and the residue partitioned between DCM and 2M NaOH solution. The aqueous was further extracted with DCM (×2) and the combined organics concentrated in vacuo. The residue was re-dissolved in DCM and extracted with 2M HCl (×2) which was then basified with 2M NaOH and re-extracted with DCM (×3). The combined organics were concentrated in vacuo to give the title compound (12 g). δH (CDCl3, 250 MHz) 1.66 (2H, m), 2.01 (2H, m), 2.73 (2H, m), 3.14 (2H, m), 4.34 (1H, m), 6.68 (3H, m), 7.19 (1H, m), MS (ES): MH+ 196. This whole was diluted with MeOH and treated with 1M HCl in Et2O to give the hydrochloride salt of the title compound (8.0 g).

Provenance & Evidence