Sulfuric Acid → Methyl 4-[2-fluoro-3-(methylsulfonyl)phenyl]piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To an ice cooled solution of methyl 4-[2-fluoro-3-(methylthio)phenyl]piperazine-1-carboxylate (1.4 g, 4.9 mmol) in sulfuric acid (1 M, 10 ml) was added sodium tungstate (0.016 g, 0.05 mmol) in one portion followed by droppwise addition of hydroperoxide (30%, 1.25 ml, 12.2 mmol). The reaction mixture was warmed to 55° C. and was stirred for 20 h. The reaction mixture was brought to ambient temperature and aqueous sodium hydroxide (5 M, 50 ml) was added. The aqueous phase was extracted with ethyl acetate (2×50 ml). The combined organic phase was dried (MgSO4) and evaporated to dryness to give the title compound. Yield (1.1 g). MS m/z (rel. intensity, 70 eV) 316 (M+, 58), 296 (30), 228 (bp), 216 (38), 56 (71).

Provenance & Evidence