Phosphorus oxychloride → 7-Chloro-5-[3-(trifluoromethyl)phenyl]pyrazolo[1,5-a]pyrimidine
Reaction equation
O[C:2]1[N:7]2[N:8]=[CH:9][CH:10]=[C:6]2[N:5]=[C:4]([C:11]2[CH:12]=[C:13]([C:17]([F:20])([F:19])[F:18])[CH:14]=[CH:15][CH:16]=2)[CH:3]=1.P(Cl)(Cl)([Cl:23])=O>>[Cl:23][C:2]1[N:7]2[N:8]=[CH:9][CH:10]=[C:6]2[N:5]=[C:4]([C:11]2[CH:12]=[C:13]([C:17]([F:20])([F:19])[F:18])[CH:14]=[CH:15][CH:16]=2)[CH:3]=1Participants
3
Procedure
A mixture of 1.75 g. of 7-hydroxy-5-(α,α,α-trifluoro-m-tolyl)pyrazolo[1,5-a]pyrimidine and 15 ml. of phosphorus oxychloride is refluxed for 2 hours. After evaporation at reduced pressure, ice is added to the residue and the desired compound is extracted with methylene chloride. After washing the organic layer with a saturated saline solution and drying with solid anhydrous sodium sulfate, evaporation gives the desired compound, m.p. 137°-139° C.
Workup
- additionA mixture of 1.75 g
- customAfter evaporation at reduced pressure, ice
- additionis added to the residue