Methyl Ethyl Ketone → 2,3-Dimethyl-4-(2,2,3,3,3-pentafluoropropoxy)pyridine-1-oxide

A mixture of 2,3-dimethyl-4-nitropyridine-1-oxide (2.0 g), methyl ethyl ketone (30 ml), 2,2,3,3,3-pentafluoropropanol (3.05 ml), anhydrous potassium carbonate (3.29 g) and hexamethyl phosphoric acid triamide (2.07 g) was heated at 70°-80° C. for 4.5 days under stirring, then insolubles were filtered off. The filtrate was concentrated, to which was added water. The mixture was subjected to extraction with ethyl acetate. The extract solution was dried on magnesium sulfate, followed by removing the solvent by evaporation. The residue was chromatographed on a column of silica gel (50 g), eluted with chloroform-methanol (10:1), and recrystallized from ethyl acetate-hexane to yield 2.4 g of 2,3-dimethyl-4-(2,2,3,3,3-pentafluoropropoxy)pyridine-1-oxide as colorless needles, m.p. 148°-149° C.

1. temperaturewas heated at 70°-80° C. for 4.5 days
2. filtrationinsolubles were filtered off
3. concentrationThe filtrate was concentrated, to which
4. additionwas added water
5. extractionThe mixture was subjected to extraction with ethyl acetate
6. customThe extract solution was dried on magnesium sulfate
7. customby removing the solvent
8. customby evaporation
9. customThe residue was chromatographed on a column of silica gel (50 g)
10. washeluted with chloroform-methanol (10:1)
11. customrecrystallized from ethyl acetate-hexane

ORD record

ord-caec4ebd35664d90a31f2f4e56d1db33

Source dataset

uspto-grants-1986_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04628098