Acetic Acid → 5-Chloro-6-(2,4-difluorophenyl)pyrazolo[1,5-a]pyrimidine-3-carboxylic acid methyl ester

HRID 1851235Notes

Reaction equation

HRID 1851235 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:6]=[N:7][N:8]2[C:13](Cl)=[C:12]([C:15]3[CH:20]=[CH:19][C:18]([F:21])=[CH:17][C:16]=3[F:22])[C:11]([Cl:23])=[N:10][C:9]=12)=[O:4].C(O)(=O)C>CO.C1COCC1.[Zn].[Cu]>[CH3:1][O:2][C:3]([C:5]1[CH:6]=[N:7][N:8]2[CH:13]=[C:12]([C:15]3[CH:20]=[CH:19][C:18]([F:21])=[CH:17][C:16]=3[F:22])[C:11]([Cl:23])=[N:10][C:9]=12)=[O:4]

Participants

6

Reactant 2

HCID 176Acetic AcidHCID 867030485,7-Dichloro-6-(2,4-difluorophenyl)pyrazolo[1,5-a]pyrimidine-3-carboxylic acid methyl ester

Product 1

HCID 867030475-Chloro-6-(2,4-difluorophenyl)pyrazolo[1,5-a]pyrimidine-3-carboxylic acid methyl esterYield 29.7%

Reagents, catalysts & solvents 3

HCID 10290809Zinc copper coupleCatalystHCID 887MethanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

500 mg (1.4 mmol) 5,7-Dichloro-6-(2,4-difluorophenyl)pyrazolo[1,5-a]pyrimidine-3-carboxylic acid methyl ester are dissolved in a mixture of 0.68 mL methanol and 3.9 mL THF. After addition of 0.16 mL acetic acid and 264 mg (2 mmol) zinc/copper pair, the mixture is vigorously stirred at rt over night. The reaction mixture is filtered via a glass microfibre filter and washed with plenty of methanol. The solvent has been removed and the residue purified by chromatography (silicagel, ethyl acetate/hexane). 134 mg (29.7%) of the desired product are obtained.

Workup

  1. filtrationThe reaction mixture is filtered via a glass microfibre
  2. filtrationfilter
  3. washwashed with plenty of methanol
  4. customThe solvent has been removed
  5. customthe residue purified by chromatography (silicagel, ethyl acetate/hexane)

Sources & evidence

ORD record
ord-fe637cf2adf84bc3b4204f64a1bbdc71
Source dataset
uspto-grants-2015_02
Patent number
US08957064B2

Reaction notes

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