p-Fluoronitrobenzene → HCID 15880890, compound

To a solution of 3-phenyl-5-ethylpyrazole (1.0 g, 5.8 mmol) in DMSO (5 mL) was added potassium t-butoxide (0.72 g, 6.4 mmol) followed by 4-fluoronitrobenzene (0.65 mL, 6.4 mmol). The mixture was heated at 90° C. for 1 hour, cooled to rt, and quenched with water (50 mL). The precipitate was collected by filtration, redissolved in ethyl acetate (50 mL), treated with active carbon (3 g), and filtered through diatomaceous earth. The mixture was concentrated to 5 mL, and hexane (25 mL) was added. The 1-(4′-nitrophenyl)-3-phenyl-5-ethylpyrazole was collected by filtration (1.70 g, 92%): mp 112-113° C. NMR 8.39 (2H, d), 7.79 (2H, d), 7.90 (2H, m), 7.45 (2H, m), 7.38 (1H, m), 6.66 (1H, s), 2.86 (2H, q), 1.38 (3H, t).

1. temperaturecooled to rt
2. customquenched with water (50 mL)
3. filtrationThe precipitate was collected by filtration
4. dissolutionredissolved in ethyl acetate (50 mL)
5. additiontreated with active carbon (3 g)
6. filtrationfiltered through diatomaceous earth
7. concentrationThe mixture was concentrated to 5 mL, and hexane (25 mL)
8. additionwas added
9. filtrationThe 1-(4′-nitrophenyl)-3-phenyl-5-ethylpyrazole was collected by filtration (1.70 g, 92%)

ORD record

ord-acb6cae35a26434885a56df05f606b85

Source dataset

uspto-grants-2003_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06506747B1