Acetyl chloride → 4-Chloro-2-methyl-1-oxo-1lambda~5~-pyridine

Temperature

-12.5 °C

4-nitro-2-picoline N-oxide (20 g, 130 mmol) was added to acetyl chloride (120 ml, 1688 mmol) in a nitrogen atmosphere at −25° C. The mixture was stirred at −30 to 5° C. for 4 hours and 15 minutes. After the reaction mixture was diluted with ethyl acetate (about 150 ml) and chloroform (about 100 ml), the mixture was concentrated. The residue was purified by silica gel column chromatography (NH silica gel: 200 g, elution solvent: heptane, heptane/ethyl acetate=75/25, 50/50, 25/75, ethyl acetate, ethyl acetate/methanol=20/1) to obtain the title compound (3.14 g) as brown oil. Simultaneously, a crude product (about 17 g) was obtained. The crude product thus obtained was further purified by silica gel column chromatography (NH silica gel: 300 g, elution solvent: heptane, heptane/ethyl acetate=75/25, 40/60, 25/75, ethyl acetate) to obtain the title compound (5.39 g) separately as brown oil.

1. concentrationthe mixture was concentrated
2. customThe residue was purified by silica gel column chromatography (NH silica gel: 200 g, elution solvent: heptane, heptane/ethyl acetate=75/25, 50/50, 25/75, ethyl acetate, ethyl acetate/methanol=20/1)

ORD record

ord-c560f1d334ee40edb6e6c2759a7d6556

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08124780B2