Phosphorus oxychloride → 3-Benzenesulphonyl-7-chloro-5-methyl-pyrazolo[1,5-a]pyrimidine

HRID 636420Notes

Reaction equation

HRID 636420 reaction equation
[C:1]1([S:7]([C:10]2[CH:11]=[N:12][N:13]3[CH:18]=[CH:17][C:16]([CH3:19])=[N:15][C:14]=23)(=[O:9])=[O:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.O=P(Cl)(Cl)[Cl:22]>>[C:1]1([S:7]([C:10]2[CH:11]=[N:12][N:13]3[C:18]([Cl:22])=[CH:17][C:16]([CH3:19])=[N:15][C:14]=23)(=[O:9])=[O:8])[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 21255037HCID 21255037, compound

Product 1

HCID 212550003-Benzenesulphonyl-7-chloro-5-methyl-pyrazolo[1,5-a]pyrimidineYield 87%

Procedure

A suspension of 0.91 g (3.14 mmol) of 3-benzenesulphonyl-5-methyl-pyrazolo[1,5-a]pyrimidine in 15 ml of POCl3 was heated at reflux for 1 hr. The reaction solution was cooled to RT and evaporated. The residue was treated with 30 ml of ice-water and the pH value of the solution was adjusted to 8 with sat. NaHCO3 solution. The aqueous phase was extracted three times with 20 ml of CH2Cl2, and the organic phases were dried (MgSO4), filtered and evaporated. Chromatography (SiO2, CH2Cl2/AcOEt 19:1) of the residue yielded 0.84 g (87%) of 3-benzenesulphonyl-7-chloro-5-methyl-pyrazolo[1,5-a]pyrimidine as a beige solid.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 1 hr
  3. customevaporated
  4. additionThe residue was treated with 30 ml of ice-water
  5. extractionThe aqueous phase was extracted three times with 20 ml of CH2Cl2
  6. dry with materialthe organic phases were dried (MgSO4)
  7. filtrationfiltered
  8. customevaporated

Sources & evidence

ORD record
ord-23ebe213e1ec4ae587df2e85717abd59
Source dataset
uspto-grants-2001_02
Patent number
US06194410B1

Reaction notes

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