N,N-Dimethylaniline → 7-Chloro-5-(4-chlorophenyl)pyrazolo[1,5-a]pyrimidine

HRID 2224404Notes

Reaction equation

HRID 2224404 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:13]=[C:12](O)[N:11]3[N:15]=[CH:16][C:17](C([O-])=O)=[C:10]3[N:9]=2)=[CH:4][CH:3]=1.P(Cl)(Cl)([Cl:23])=O.CN(C)C1C=CC=CC=1>>[Cl:23][C:12]1[N:11]2[N:15]=[CH:16][CH:17]=[C:10]2[N:9]=[C:8]([C:5]2[CH:6]=[CH:7][C:2]([Cl:1])=[CH:3][CH:4]=2)[CH:13]=1

Participants

4

Reactant 3

HCID 949N,N-DimethylanilineHCID 24813Phosphorus oxychlorideHCID 178524812HCID 178524812, compound

Product 1

HCID 210357027-Chloro-5-(4-chlorophenyl)pyrazolo[1,5-a]pyrimidineYield 85.8%

Conditions

Temperature
100 °C

Procedure

A mixture of 5-(4-chloro-phenyl)-7-hydroxy-pyrazolo[1,5-a]pyrimidine-3-carboxylate (9.53 g, 0.03 mol), phosphorous oxychloride (11.0 mL, 0.12 mol), and N,N-dimethylaniline (1.3 mL, 0.01 mol) was stirred for 2 h at 100° C. The mixture was evaporated in vacuo and the residue was partitioned between water and dichloromethane. The organic phase was washed with water, dried (Na2SO4) and evaporated in vacuo. The remaining solid was crystallized from ethyl acetate/hexane to give 7-chloro-5-(4-chloro-phenyl)-pyrazolo[1,5-a]pyrimidine (6.80 g, 67%). Pale-yellow solid, MS (ISP) 336.0 [(M+H)+]; mp 133-135° C.

Workup

  1. customThe mixture was evaporated in vacuo
  2. customthe residue was partitioned between water and dichloromethane
  3. washThe organic phase was washed with water
  4. dry with materialdried (Na2SO4)
  5. customevaporated in vacuo
  6. customThe remaining solid was crystallized from ethyl acetate/hexane

Sources & evidence

ORD record
ord-92c6741826e54692bfa113c9a78fef45
Source dataset
uspto-grants-2008_05
Patent number
US07378417B2

Reaction notes

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