Nitromethane → 1-[3-chloro-4-(2-nitroethenyl)phenyl]-3-(trifluoromethyl)-1H-pyrazole

To a solution of 2-chloro-4-[3-(trifluoromethyl)-1H-pyrazol-1-yl]benzaldehyde (i.e. the product of Step A; 6.0 g, 0.025 mol) in acetic acid (24 mL) was added ammonium acetate (5.6 g, 73 mmol), and the resulting mixture was stirred for 15 min at 0° C. Nitromethane (12.5 g, 204 mmol) was then added, and the mixture was stirred at 80° C. for 2 h. The reaction mixture was poured into ice water and extracted with ethyl acetate (100 mL). The aqueous layer was extracted with ethyl acetate (2×250 mL), and the combined organic layers were washed with brine (200 mL), dried (Na2SO4) and concentrated under reduced pressure. The residue was purified by flash column chromatography on silica gel eluted with 30% ethyl acetate in hexanes to afford the title compound (7.1 g).

1. stirringthe mixture was stirred at 80° C. for 2 h
2. extractionextracted with ethyl acetate (100 mL)
3. extractionThe aqueous layer was extracted with ethyl acetate (2×250 mL)
4. washthe combined organic layers were washed with brine (200 mL)
5. dry with materialdried (Na2SO4)
6. concentrationconcentrated under reduced pressure
7. customThe residue was purified by flash column chromatography on silica gel
8. washeluted with 30% ethyl acetate in hexanes

ORD record

ord-6190e89cf2c84a46ae6ff93ddb36f13f

Source dataset

uspto-grants-2014_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08815772B2