Trifluoroacetic acid → N-[4-Fluoro-3-(methyloxy)phenyl]-4-piperidinamine

Participants

Reaction Steps

A solution of 1,1-dimethylethyl 4-{[4-fluoro-3-(methyloxy)phenyl]amino}-1-piperidinecarboxylate (D9) (1.45 g, 4.48 mmol) in DCM (16 ml) was cooled in an ice bath and TFA (4 ml) was added. The reaction mixture was stirred for 1 h, then warmed to room temperature and stirred for 2 h. The solvent was removed in vacuo and the residue partitioned between EtOAc and saturated aqueous NaHCO3 solution. The organic phase was washed with further saturated aqueous NaHCO3 solution. The aqueous was concentrated to ˜50% volume, further basified with 2M NaOH solution and extracted with EtOAc (×2). All organic phases were combined and washed with further 2M NaOH solution, dried and concentrated to give the title compound as an orange gum (1 g). δH (DMSO-d6, 400 MHz) 6.86 (1H, dd), 6.33 (1H, dd), 6.03 (1H, m), 5.32 (1H, d), 3.74 (3H, s), 3.33 (1H, br s), 3.18 (1H, m), 2.92 (2H, m), 2.51 (2H, m), 1.83 (2H, m), 1.17 (2H, m). MS (ES): MH+ 225.

Provenance & Evidence