Reaction #674280

Reaction equation

ethyl 4-bromo-1-(3,4-difluorophenyl)-1H-pyrazole-3-carboxylate

methyl 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoate

potassium carbonate

→

Ethyl 1-(3,4-difluorophenyl)-4-[3-(ethoxycarbonyl)phenyl]-1H-pyrazole-3-carboxylate

Solvents

ethanol

Conditions

Workup

1. 1
   Temperatureheated at the boil for 4 h
2. 2
   Otherthe solvent was removed under reduced pressure
3. 3
   workup.DISSOLUTIONthe residue was dissolved in water
4. 4
   Otherdichloromethane, the phases were separated
5. 5
   Dryingthe organic phase was dried over magnesium sulfate
6. 6
   OtherThe crude product was purified by chromatography (ethyl acetate:n-heptane 1:4)

Procedure

180 mg (0.54 mmol) of ethyl 4-bromo-1-(3,4-difluorophenyl)-1H-pyrazole-3-carboxylate, 156.7 mg (0.59 mmol) of methyl 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoate, 158 mg (1.14 mmol) of potassium carbonate, 5.07 mg (0.011 mmol) of 2,2-dicyclohexylphosphino-2″,6″-diisopropoxybiphenyl and 1.22 mg (0.005 mmol) of palladium (II)acetate were suspended in 5 ml of ethanol and heated at the boil for 4 h. After cooling to room temperature, the solvent was removed under reduced pressure, the residue was dissolved in water and dichloromethane, the phases were separated and the organic phase was dried over magnesium sulfate. The crude product was purified by chromatography (ethyl acetate:n-heptane 1:4). This gave 84 mg (37%) of the desired product. 1H-NMR (400 MHz, CDCl3 δ, ppm) 8.15 (s, 1H); 8.05 (d, 1H); 7.96 (s, 1H); 7.74-7.69 (m, 2H); 7.53-7.47 (m, 2H); 7.28 (m, 1H); 4.48-4.34 (m, 4H); 1.43 (t, 3H); 1.29 (t, 3H)

Source