Phosphorus oxychloride → 7-Chloro-2,5-dimethyl-3-(4-chloro-2,6-dimethylphenyl)-pyrazolo[1,5-a]pyrimidine

HRID 842012Notes

Reaction equation

HRID 842012 reaction equation
O[C:2]1[N:7]2[N:8]=[C:9]([CH3:20])[C:10]([C:11]3[C:16]([CH3:17])=[CH:15][C:14]([Cl:18])=[CH:13][C:12]=3[CH3:19])=[C:6]2[N:5]=[C:4]([CH3:21])[CH:3]=1.C([O-])(O)=O.[Na+].O=P(Cl)(Cl)[Cl:29]>C(Cl)Cl>[Cl:29][C:2]1[N:7]2[N:8]=[C:9]([CH3:20])[C:10]([C:11]3[C:16]([CH3:17])=[CH:15][C:14]([Cl:18])=[CH:13][C:12]=3[CH3:19])=[C:6]2[N:5]=[C:4]([CH3:21])[CH:3]=1

Participants

5

Reactant 3

HCID 24813Phosphorus oxychlorideHCID 516892Sodium BicarbonateHCID 178429165HCID 178429165, compound

Product 1

HCID 184069827-Chloro-2,5-dimethyl-3-(4-chloro-2,6-dimethylphenyl)-pyrazolo[1,5-a]pyrimidine

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Slurry 7-hydroxy-2,5-dimethyl-3-(4-chloro-2,6-dimethylphenyl)-pyrazolo[1,5-a] pyrimidine in 10 mL POCl3 and reflux at 130° C. under N2. After 2 hours, monitoring by TLC (alcohol Rf=0.5, chloride Rf=1.0; EtOAc as eluent), quench the reaction carefully at ambient temperature by diluting with 50 mL CH2Cl2 and pouring slowly into non-stirring saturated NaHCO3. Adjust stirring speed to control rate of quenching of residual POCl3 and stir until gas evolution ceases. Separate the layers and extract the aqueous layer with CH2Cl2 (2×50 mL). Pool the organic layers and dry over Na2SO4. Filter and evaporate to yellow oil, which is used directly without further purification.

Workup

  1. custommonitoring by TLC (alcohol Rf=0.5, chloride Rf=1.0; EtOAc as eluent), quench
  2. customthe reaction carefully at ambient temperature
  3. customof quenching of residual POCl3
  4. stirringstir until gas evolution ceases
  5. customSeparate the layers
  6. extractionextract the aqueous layer with CH2Cl2 (2×50 mL)
  7. dry with materialPool the organic layers and dry over Na2SO4
  8. filtrationFilter
  9. customevaporate to yellow oil, which
  10. customis used directly without further purification

Sources & evidence

ORD record
ord-f32c1ed1e48148129720f054b476d377
Source dataset
uspto-grants-2002_04
Patent number
US06372743B1

Reaction notes

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