Hydrochloric Acid → 1-(2-Fluoropyridin-4-yl)-2-(3-trifluoromethylphenyl)ethane-1,2-dione-1-oxime

To a mixture of 2-(2-fluoropyridin-4-yl)-1-(3-trifluoromethylphenyl)ethanone (10.80 g, 0.038 mol) in ethanol (200 mL), at −10° C., under argon, was added tert-butyl nitrite (5.0 mL, 0.042 mol) and hydrogen chloride (12.2 mL, 2.5M in ethanol, 0.031 mol) dropwise while maintaining the temperature below −5° C. Upon completion of addition, the reaction was allowed to warm to RT for 2 hrs. The reaction mixture was then concentrated in vacuo, diluted with water (100 mL), basified with saturated sodium bicarbonate (200 ml), and extracted with ethyl acetate (3×400 mL). The combined organic layers were washed with water (300 mL), dried with brine (300 mL) and anhydrous sodium sulfate, filtered and concentrated to yield 11.4 g of the title compound, as an oil.

1. temperaturewhile maintaining the temperature below −5° C
2. additionUpon completion of addition
3. concentrationThe reaction mixture was then concentrated in vacuo
4. additiondiluted with water (100 mL)
5. extractionextracted with ethyl acetate (3×400 mL)
6. washThe combined organic layers were washed with water (300 mL)
7. dry with materialdried with brine (300 mL) and anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated

ORD record

ord-d0751a2f8cd0480680bec22df0e7874c

Source dataset

uspto-grants-2001_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06291457B1