Phosphorus oxychloride → 2-(3-Chlorophenyl)-4-chloro-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone

HRID 381926Notes

Reaction equation

HRID 381926 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([N:8]2[C:13](=[O:14])[C:12](O)=[C:11]([C:16]3[CH:21]=[CH:20][C:19]([S:22]([CH3:25])(=[O:24])=[O:23])=[CH:18][CH:17]=3)[CH:10]=[N:9]2)[CH:5]=[CH:6][CH:7]=1.O=P(Cl)(Cl)[Cl:28]>>[Cl:1][C:2]1[CH:3]=[C:4]([N:8]2[C:13](=[O:14])[C:12]([Cl:28])=[C:11]([C:16]3[CH:21]=[CH:20][C:19]([S:22]([CH3:25])(=[O:24])=[O:23])=[CH:18][CH:17]=3)[CH:10]=[N:9]2)[CH:5]=[CH:6][CH:7]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178504686HCID 178504686, compound

Product 1

HCID 219343772-(3-Chlorophenyl)-4-chloro-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinoneYield 29%

Procedure

A solution of 2-(3-chlorophenyl)-4-hydroxy-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone, prepared in Example 332, in POCl3 was heated to reflux for 3 hours while stirring under nitrogen. The mixture was cooled to room temperature and poured into ice with constant swirling. The resulting white solid was extracted with ethyl acetate. The combined organics were washed with H2O, dried over MgSO4, and concentrated to a solid. The crude product was purified using flash chromatography (SiO2, eluting with 1:1 ethyl acetate/hexanes) to provide the desired product (yield: 0.151 g, 29%). mp 203-204° C. 1H NMR (300 MHz, DMSO d6) δ 3.29-3.36 (3H, obstructed by H2O), 7.60 (m, 3H), 7.76 (m, 1H), 7.92 (m, 2H), 8.14 (m, 2H), 8.25 (s, 1H). MS (DCI/NH3) m/z 395 (M+H)+, 412 (M+NH4)+. Anal. calc. for C17H12Cl2N2O3S: C, 51.66; H, 3.06; N, 7.09. Found: C, 51.67; H, 3.03; N, 6.93.

Workup

  1. temperaturewas heated
  2. temperatureto reflux for 3 hours
  3. additionpoured into ice with constant swirling
  4. extractionThe resulting white solid was extracted with ethyl acetate
  5. washThe combined organics were washed with H2O
  6. dry with materialdried over MgSO4
  7. concentrationconcentrated to a solid
  8. customThe crude product was purified
  9. washflash chromatography (SiO2, eluting with 1:1 ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-b67b562777ea42d1bb61af2c5db85363
Source dataset
uspto-grants-2001_10
Patent number
US06307047B1

Reaction notes

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