N-OXIDE-2,4-DIMETHYL-3-PYRIDINE CARBOXYLIC ACID ETHYL ESTER synthesis

Yield:405058-67-5 100%

Reaction Conditions:

with 3-chloro-benzenecarboperoxoic acid in dichloromethane at 20; for 48 h;

Steps:

To a solution of 2,4-dimethyl-nicotinic acid ethyl ester (1.79 g, 10.0 mmol) in CH₂Cl₂ (50 mL) was added 3-chloroperoxybenzoic acid (77% max., 4.48 g, 20.0 mmol). The mixture was stirred at room temperature for 2 days, and then concentrated under reduced pressure. The residual solid was purified by flash column chromatography on silica gel (EtOAc) to afford 2,4-dimethyl-1-oxy-nicotinic acid ethyl ester as a white solid (1.95 g, 100%). ¹H NMR (CDCl₃) δ 1.41 (t, 3H, J=7.2 Hz), 2.30 (s, 3H), 2.49 (s, 3H), 4.44 (q, 2H, J=7.2 Hz), 7.00 (d, 1H, J=6.6 Hz), 8.19 (d, 1H, J=6.6 Hz).

References:

US2005/277668,2005,A1 Location in patent:Page/Page column 16