Phosphorus oxychloride → 3-Benzenesulphonyl-7-chloro-5-methyl-2-methylsulphanyl-pyrazolo[1,5-a]pyrimidine

HRID 636380Notes

Reaction equation

HRID 636380 reaction equation
[C:1]1([S:7]([C:10]2[C:11]([S:21][CH3:22])=[N:12][N:13]3[C:18](O)=[CH:17][C:16]([CH3:20])=[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:25]>>[C:1]1([S:7]([C:10]2[C:11]([S:21][CH3:22])=[N:12][N:13]3[C:18]([Cl:25])=[CH:17][C:16]([CH3:20])=[N:15][C:14]=23)(=[O:9])=[O:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178503606HCID 178503606, compound

Product 1

HCID 109810973-Benzenesulphonyl-7-chloro-5-methyl-2-methylsulphanyl-pyrazolo[1,5-a]pyrimidineYield 94%

Procedure

A suspension of 3.0 g (8.94 mmol) of 3-benzenesulphonyl-5-methyl-2-methylsulphanyl-pyrazolo[1,5-a]pyrimidin-7-ol in 20 ml of POCl3 was heated at reflux for 45 min. The reaction solution was cooled to RT and evaporated in a high vacuum. The residue was treated with 100 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 100 ml of CH2Cl2, and the organic phases were dried (MgSO4), filtered and evaporated. Chromatography (SiO2, CH2Cl2/AcOEt 19:1) of the residue yielded 3.0 g (94%) of 3-benzenesulphonyl-7-chloro-5-methyl-2-methylsulphanyl-pyrazolo[1,5-a]pyrimidine as pale yellow crystals, m.p. 163-165° C.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 45 min
  3. customevaporated in a high vacuum
  4. additionThe residue was treated with 100 ml of ice-water
  5. extractionThe aqueous phase was extracted three times with 100 ml of CH2Cl2
  6. dry with materialthe organic phases were dried (MgSO4)
  7. filtrationfiltered
  8. customevaporated

Sources & evidence

ORD record
ord-072e279a76dd4cf6afa00c8d00a7271e
Source dataset
uspto-grants-2001_02
Patent number
US06194410B1

Reaction notes

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