3-Chloroperoxybenzoic acid (77%, 58.04 g, 259 mmol, 1.1 eq.) was added slowly as a solid to a suspension of 5-hydroxy-2-methylpyridine (25.44 g, 233 mmol) in chloroform (600 ml). After all the solid had dissolved to leave a clear yellow solution, the reaction was stirred at reflux (75°C) for 2 h. After this time the solution was allowed to cool to ambient temperature before the solvent was removed under reduced pressure. The crude yellow solid was washed with hot ethyl acetate (3 × 300 ml) and dried overnight in vacuo. Yield = 22.33 g, 77%.

• Reaction can be carried out on smaller or larger scale with relative ease
• Add mCPBA slowly (exothermic reaction)

¹H NMR (400 MHz, 298 K, DMSO) δ_H 10.24 (1H, br s, OH), 7.81 (1H, d, ⁴J_HH = 2.0 Hz, Py), 7.24 (1H, d, ³J_HH = 8.5 Hz, Py), 6.77 (1H, dd, ³J_HH = 8.5 Hz , ⁴J_HH = 2.0 Hz, Py), 2.22 (3H, s, CH₃).

¹³C{¹H} NMR (100 MHz, 298K, DMSO) δ_C 153.9 (Py), 138.9 (Py), 127.3 (Py), 126.0 (Py), 113.7 (Py), 16.2 (CH₃).

MS (ESI) m/z 126.3 [M+H]⁺, 148.2 [M+Na]⁺.

IR v cm^-1 2215 w, 1622 w, 1570 w, 1529 m, 1459 m, 1422 m, 1386 m, 1309 m, 1275 w, 1226 w, 1663 m, 1117 m, 1001 m, 961 m, 887 m, 863 s, 825 s, 775 m, 740 s, 692 m.

Elemental Analysis found (Calculated for C₆H₇NO₂) % C 57.57 (57.59), H 5.62 (5.64), N 11.05 (11.19).