Reaction #684984

Reaction equation

5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4,5-dihydro-pyrazole-3-carboxylic acid

ethanol

p-toluenesulfonic acid monohydrate

→

title compound

5-(4-Chloro-phenyl)-1-(2,4-dichloro-phenyl)-4,5-dihydro-1H-pyrazol-3-carboxylic acid ethyl ester

Solvents

toluene

Conditions

Workup

1. 1
   TemperatureAfter cooling to room temperature
2. 2
   Washthe reaction mixture washed with sodium hydrogen carbonate solution and water
3. 3
   Dryingdried over sodium sulphate
4. 4
   Otherevaporated to dryness

Procedure

5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4,5-dihydro-pyrazole-3-carboxylic acid (0.55 g, 1.50 mmol) was dissolved in 20 mL of toluene and (2 mL) ethanol and (0.05 g) of p-toluenesulfonic acid monohydrate were added. The mixture was heated at 80° C. for 72 hours. After cooling to room temperature, the reaction mixture washed with sodium hydrogen carbonate solution and water, dried over sodium sulphate and evaporated to dryness to give the title compound in form of oil.

Source