2,3,5-Trimethylpyridine → 2,3,5-Trimethyl-1-oxidopyridin-1-ium

To a dichloromethane (dehydrated) (150 ml) solution of a 2,3,5-collidine (11.0 g, 90.8 mmol), 3-chloroperbenzoic acid (24.8 g, 93.4 mmol as the content was regarded as 65%) was added at 1° C. in a nitrogen atmosphere. The mixture was stirred while the temperature was gradually raised to room temperature for 13.5 hours. After the reaction mixture was concentrated, the residue was purified by silica gel column chromatography (NH silica gel: 200 g, elution solvent: heptane/ethyl acetate=50/50, ethyl acetate, ethyl acetate/methanol=20/1) to obtain a crude product of the title compound as a pale yellow oil. After the crude product was diluted with ethyl acetate and a saturated aqueous solution of sodium hydrogen carbonate, the mixture was concentrated. The residue was purified by silica gel column chromatography (NH silica gel: 300 g, elution solvent: heptane, heptane/ethyl acetate=50/50, ethyl acetate, ethyl acetate/methanol=20/1) to obtain the title compound (11.0 g, yield: 88.3%) as a white solid.

1. additionwas added at 1° C. in a nitrogen atmosphere
2. concentrationAfter the reaction mixture was concentrated
3. customthe residue was purified by silica gel column chromatography (NH silica gel: 200 g, elution solvent: heptane/ethyl acetate=50/50, ethyl acetate, ethyl acetate/methanol=20/1)

ORD record

ord-cb3270638a564270bdd152959670e67f

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08124780B2