Hexachloroethane → HCID 86679965, compound

Temperature

-70 °C

To a stirred solution of 1-(2,2-difluoroethyl)-4-nitro-1H-pyrazole (1.0 g, 5.13 mmol) in dry THF (20 mL) cooled to −70° C. was added dropwise a solution of lithium hexamethyldisilazide (1 M in THF, 8.47 mL, 8.47 mmol). After stirring at −70° C. for 40 min, the reaction mixture was allowed to warm to −55° C. over 20 min. After recooling to −70° C., a solution of perchloroethane (1.74 g, 7.34 mmol) in THF (10 mL) was added slowly and the reaction mixture was stirred at −70° C. for 1.5 hr. Saturated aqueous ammonium chloride solution (30 mL) was added followed by water (15 mL) and the mixture was extracted with EtOAc (3×100 mL). The combined organic layers were dried over MgSO4 and the solvent removed under reduced pressure. Purification of the residue by silica gel column chromatography (0-100% EtOAc/isohexane) gave 5-chloro-1-(2,2-difluoroethyl)-4-nitro-1H-pyrazole as an off-white solid (438 mg, 37%). 1H NMR (400 MHz, CDCl3) δ 8.24 (s, 1H), 6.18 (tt, J=54.8, 4.2 Hz, 1H), 4.58 (td, J=12.8, 4.2 Hz, 2H).

1. temperatureto warm to −55° C. over 20 min
2. customAfter recooling to −70° C.
3. stirringthe reaction mixture was stirred at −70° C. for 1.5 hr
4. extractionthe mixture was extracted with EtOAc (3×100 mL)
5. dry with materialThe combined organic layers were dried over MgSO4
6. customthe solvent removed under reduced pressure
7. customPurification of the residue by silica gel column chromatography (0-100% EtOAc/isohexane)

ORD record

ord-29f3ce94739b42d8a296f84d5d9a412a

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09328106B2