Phosphorus oxychloride → 5-Chloro-2,6-dimethyl-2,3-dihydropyridazin-3-one

Temperature

85 °C

A mixture of 5-hydroxy-2,6-dimethylpyridazin-3(2H)-one (736 mg, 5.25 mmol) and POCl3 (4.5 mL) was stirred at 85° C. for 2 hours. The reaction mixture was concentrated under reduced pressure to give the crude material that was quenched with saturated aqueous Na2CO3. The resulting mixture was stirred for 2 hours and extracted with EtOAc (3×). The combined organic layers were dried over MgSO4, filtered, and concentrated under reduced pressure to give 587 mg (70%) of the desired product that was used directly without further purification.

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. customto give the crude material that
3. customwas quenched with saturated aqueous Na2CO3
4. stirringThe resulting mixture was stirred for 2 hours
5. extractionextracted with EtOAc (3×)
6. dry with materialThe combined organic layers were dried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure

ORD record

ord-a03ba4a8802a405ea2ff7728eec2195e

Source dataset

uspto-grants-2010_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07732616B2