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

HRID 891345Notes

Reaction equation

HRID 891345 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-28c6cc9195a84d2fadf712e1cee5f57e
Source dataset
uspto-grants-2006_02
Patent number
US07001895B2

Reaction notes

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