To a solution of (3R)-1-[(4-chlorophenyl)sulfonyl]-3-methylpiperazine (0.15 g, 0.55 mmol) in dry acetonitrile (5 mL) was added potassium carbonate (90 mg, 0.66 mmol) and 2-pyridinecarbonyl chloride (106 mg, 0.60 mmol) and the reaction mixture heated at 85° C. for 24 h. To the mixture was added ethyl acetate (30 mL) and the organic phase washed with 10% aqueous sodium bicarbonate (50 mL) before it was dried (MgSO4), filtered and the solvent evaporated. The crude product was purified by Biotage SP4 (12+M silica column) eluting 0-4% MeOH in DCM to give the title compound as an off-white solid (95 mg).
