Sulfuric Acid → 1-Ethyl-4-(2-fluoro-3-(methylthio)phenyl)-1,2,3,6-tetrahydropyridine

Participants

Reaction Conditions

Reaction Steps

A mixture of 1-ethyl-4-[2-fluoro-3-(methylthio)phenyl]piperidin-4-ol (42 g, 156 mmol), sulphuric acid (conc, 8.5 ml) and toluene (200 ml) was heated in a Dean-Stark trap for 20 h. The mixture was cooled to 70° C., water (200 ml) was added and the phases were separated. The aqueous phase was basified with aqueous sodium hydroxide (5 M) and extracted with ethyl acetate (2×50 ml). The combined organic phases was dried (MgSO4) and evaporated to dryness to give the title compound (22.6 g). MS m/z (rel. intensity, 70 eV) 251 (M+, bp), 236 (85), 147 (65), 146 (45), 110 (44).

Provenance & Evidence