Dimethyl Sulfoxide → (4-Chloro-3-difluoromethoxy-2-pyridyl)cyclopropylketone

Temperature

-78 °C

6.44 ml of oxalyl chloride was dissolved in 150 ml of anhydrous dichloromethane, under cooling at −78° C., 75 ml of anhydrous dichloromethane solution of 5.64 ml of anhydrous dimethylsulfoxide was dropped. The resulting mixture was stirred at −78° C. for 40 minutes, and thereafter, 150 ml of anhydrous dichloromethane solution of 14.17 g of (4-chloro-3-difluoromethoxy-2-pyridyl)cyclopropylmethane-1-ol (IX) was dropped thereto. The resulting mixture was stirred at −78° C. for 30 minutes, and thereafter, the reaction temperature was elevated to −45° C., and the resulting mixture was stirred at the same temperature for 1 hour, and thereafter, 39.56 ml of triethylamine was dropped and the temperature of the resulting mixture was elevated to a room temperature. Water was added thereto and the resulting mixture was extracted with chloroform, and the resulting organic layer was washed with water and saturated salt water, and thereafter, dried over anhydrous sodium sulfate and the solvent was distilled off under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluent; chloroform:ethyl acetate=125:1) to obtain 12.57 g of (4-chloro-3-difluoromethoxy-2-pyridyl)cyclopropylketone (X).

1. stirringThe resulting mixture was stirred at −78° C. for 30 minutes
2. customwas elevated to −45° C.
3. stirringthe resulting mixture was stirred at the same temperature for 1 hour
4. customwas elevated to a room temperature
5. extractionthe resulting mixture was extracted with chloroform
6. washthe resulting organic layer was washed with water and saturated salt water
7. dry with materialdried over anhydrous sodium sulfate
8. distillationthe solvent was distilled off under reduced pressure
9. customThe resulting residue was purified by silica gel column chromatography (eluent; chloroform:ethyl acetate=125:1)

ORD record

ord-c10a1693e6874b4499f5425116fa76ae

Source dataset

uspto-grants-2003_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06525066B2