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

HRID 900895Notes

Reaction equation

HRID 900895 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 AcOEt/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 AcOEt/hexane

Sources & evidence

ORD record
ord-393d68aa2e5d4a8c89cdd5f00c1109df
Source dataset
uspto-grants-2008_04
Patent number
US07361659B2

Reaction notes

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