Azobisisobutyronitrile → 4-Chloro-3-(4-chlorophenylsulfonylmethyl)pyridine

A carbon tetrachloride (15 ml) suspension of 4-chloro-3-methylpyridine hydrochloride (402 mg, 2.45 mmol), N-chlorosuccinic acid imide (327 mg, 2.45 mmol) and 2,2′-azobis(2-methylpropionitrile) (30 mg, 0.183 mmol) was heated under reflux for 13 hours under a nitrogen atmosphere. After cooling to room temperature, the reaction mixture was concentrated under reduced pressure. The residue was dissolved in butanol (10 ml), followed by the addition of sodium 4-chlorophenylsulfinate (487 mg, 2.45 mmol) and potassium acetate (481 mg, 4.90 mmol). The mixture was stirred at 70° C. for 24 hours. The reaction mixture was cooled to room temperature, followed by concentration under reduced pressure. Ethyl acetate was added to the residue. The mixture was washed successively with a saturated aqueous solution of sodium bicarbonate and brine and then, dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The residue was subjected to chromatography on a silica gel column, and the fraction obtained from the hexane:ethyl acetate (=2:1) eluate was concentrated under reduced pressure, whereby the title compound (130 mg, 18%) was obtained as a white solid.

1. temperaturewas heated
2. temperatureunder reflux for 13 hours under a nitrogen atmosphere
3. concentrationthe reaction mixture was concentrated under reduced pressure
4. dissolutionThe residue was dissolved in butanol (10 ml)
5. temperatureThe reaction mixture was cooled to room temperature
6. concentrationfollowed by concentration under reduced pressure
7. additionEthyl acetate was added to the residue
8. washThe mixture was washed successively with a saturated aqueous solution of sodium bicarbonate and brine
9. dry with materialdried over anhydrous sodium sulfate
10. filtrationAfter filtration
11. concentrationthe filtrate was concentrated under reduced pressure
12. customthe fraction obtained from the hexane
13. concentrationethyl acetate (=2:1) eluate was concentrated under reduced pressure, whereby the title compound (130 mg, 18%)
14. customwas obtained as a white solid

ORD record

ord-38561990dec44fa2b65b8768e7cf0f95

Source dataset

uspto-grants-2008_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07399775B2