Hydrogen Peroxide → (+/-)-6-[2-Methyl-4-(3-phenyl-piperidin-1ylmethyl)-phenoxy]-nicotinamide methanesulfonate

Participants

Reaction Steps

Combine (±)-6-[2-methyl-4-(3-phenyl-piperidinylmethyl)-phenoxy]-nicotinonitrile (compound of example 365, step 2) (0.878 g, 2.29 mmol) and potassium carbonate (0.159 g, 1.15 mmol) in dimethylsulfoxide (11.0 mL,). Treat the mixture with 30% hydrogen peroxide solution (aq) (0.77 mL, 6.79 mmol), and stir at ambient temperature. After 4 h, dilute the reaction mixture with water (25 mL) and extract with ethyl acetate (3×30 mL). Wash combined ethyl acetate extracts with brine, dry over anhydrous magnesium sulfate, filter, and concentrate. Crude product is pure by 1H NMR and reverse-phase HPLC. Dissolve product in tetrahydrofuran (12 mL) and treat with methanesulfonic acid (0.148 mL, 2.28 mmol). White precipitate forms and turns oily within 3 minutes. Dissolve residue in tetrahydrofuran and concentrate. Product purity is 82% by reverse-phase HPLC. Purify residue by reverse-phase HPLC. Concentrate fractions containing pure product, recrystallize from methanol:diethyl ether (2:5, 16 mL), and isolate product by vacuum filtration to provide 0.0941 g (10%) of the title compound as white/tan crystals: high resolution mass spectrum (electrospray): m/z calc for C25H28N3O2 402.2182, found 402.2172; 1H NMR (methanol-d4): 8.62 (d, 1H, J=2.0 Hz), 8.36 (dd, 1H, J=2.4, 8.8 Hz), 7.57-7.54 (m, 1H), 7.48 (dd, 1H, J=1.5, 7.8 Hz), 7.43-7.38 (m, 2H), 7.37-7.30 (m, 3H), 7.23 (d, 1H, J=8.3 Hz), 7.16 (d, 1H, J=8.8 Hz), 4.45-4.36 (m, 2H), 3.63 (t, 2H, J=14.6 Hz), 3.22 (t, 1H, J=12.2 Hz), 3.17-3.07 (m, 2H), 2.23 (s, 3H), 2.20-2.13 (m, 1H), 2.12-2.92 (m, 2H), 1.86 (dq, 1H, J=3.9, 12.2 Hz).

Provenance & Evidence