合成路线1

The reaction of 3-(1-propylpiperidin-3(S)-yl)phenol (I) with trifluoromethanesulfonic anhydride gives the triflate (II), which is treated with Pd(OAc)4, CO and MeOH, yielding 3-(1-propylpiperidin-3(S)-yl)benzoic acid methyl ester (III). The reaction of (III) with sodium azide and H2SO4 affords the aniline (IV), which by reaction with NaNO2, HBr and CuBr provides 3(S)-(3-bromophenyl)-1-propylpiperidine (V). The reaction of (V) with dimethyl disulfide and n-BuLi gives the thioether (VI), which is oxidized with MCPBA to afford the target sulfone, which is easily separated from the N-oxide (VII) also formed in the oxidation process. The N-oxide (VII) can be reduced to the target compound by means of TiCl4 and NaI in acetonitrile.