Phosphorus oxychloride → 3-Chloro-5-(trifluoromethyl)pyridazine

Temperature

80 °C

5-(Trifluoromethyl)pyridazin-3(2H)-one (20.0 g, 111 mmol) was dissolved in 1,4-dioxane (222 mL) and POCl3 (31.0 mL, 333 mmol) added. The reaction was left to stir at 80° C. for 3 h. After consumption of the starting material, the reaction was cooled to room temperature. The reaction mixture was added to ice and quenched with ammonium hydroxide. The aqueous layer was extracted with dichloromethane (×3) and the organic layers combined, dried with magnesium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by flash chromatography to afford the title compound as an orange oil. 1H NMR (500 MHz, CDCl3) δ 9.37 (s, 1H); 7.76 (s, 1H).

1. waitThe reaction was left
2. customAfter consumption of the starting material
3. temperaturethe reaction was cooled to room temperature
4. additionThe reaction mixture was added to ice
5. customquenched with ammonium hydroxide
6. extractionThe aqueous layer was extracted with dichloromethane (×3)
7. dry with materialdried with magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customThe residue was purified by flash chromatography

ORD record

ord-f4ddc911ac3e4a54bad9f664dda0f152

Source dataset

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08592425B2