5,7-Dichloro-6-(2,6-difluorophenyl)pyrazolo[1,5-a]pyrimidine-3-carboxylic acid methyl ester → 5-Chloro-6-(2,6-difluorophenyl)pyrazolo[1,5-a]pyrimidine-3-carboxylic acid methyl ester
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[C:20]([F:21])=[CH:19][CH:18]=[CH:17][C:16]=3[F:22])[C:11]([Cl:23])=[N:10][C:9]=12)=[O:4]>C(O)C.O.C1COCC1.[Zn]>[CH3:1][O:2][C:3]([C:5]1[CH:6]=[N:7][N:8]2[CH:13]=[C:12]([C:15]3[C:20]([F:21])=[CH:19][CH:18]=[CH:17][C:16]=3[F:22])[C:11]([Cl:23])=[N:10][C:9]=12)=[O:4]Participants
6
Reactant 1
Product 1
Reagents, catalysts & solvents 4
Procedure
5 g (13.96 mmol) 5,7-Dichloro-6-(2,6-difluorophenyl)pyrazolo[1,5-a]pyrimidine-3-carboxylic acid methyl ester are dissolved in a mixture of 355 mL ethanol, 253 mL water and 136 mL THF. After addition of 5.8 g (89 mmol) zinc in portions, the mixture is vigorously stirred at rt for three hours. Stirring is continued over night. The reaction mixture is filtered via a glass microfibre filter and washed with plenty of ethanol. The solvent has been removed and the residue redissolved in ethyl acetate. After washing twice with brine and drying over Na2SO4, the solvent is evaporated and the residue is used in the next step as the crude contaminated product (2.3 g=51%).
Workup
- stirringStirring
- waitis continued over night
- filtrationThe reaction mixture is filtered via a glass microfibre
- filtrationfilter
- washwashed with plenty of ethanol
- customThe solvent has been removed
- dissolutionthe residue redissolved in ethyl acetate
- washAfter washing twice with brine
- dry with materialdrying over Na2SO4
- customthe solvent is evaporated
Sources & evidence
- ORD record
- ord-b3c6a6e76e3949e0b68edd5ca03c071c
- Source dataset
- uspto-grants-2015_02
- Patent number
- US08957064B2
Reaction notes
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