Reaction #657307

Reaction equation

methyl 3-(4-fluorophenyl)-3-oxopropanoate

hydrazine hydrate

diethyl ether

→

3-(4-fluorophenyl)-1H-pyrazol-5-ol

Solvents

acetic acid

Conditions

Workup

1. 1
   Temperatureis heated 3 h
2. 2
   Temperatureunder reflux
3. 3
   TemperatureThe resulting suspension is cooled down
4. 4
   FiltrationThe precipitate is filtered off
5. 5
   Dryingdried in vacuo and 9 g (100%) of 3-(4-fluorophenyl)-1H-pyrazol-5-ol
6. 6
   Otherare obtained as white solid

Procedure

A mixture of methyl 3-(4-fluorophenyl)-3-oxopropanoate (10.0 g, 0.051 mol) and hydrazine hydrate (1.1 eq, 2.8 g, 0.056 mol) in 20 mL glacial acetic acid is heated 3 h under reflux. The resulting suspension is cooled down and 10 mL diethyl ether is added. The precipitate is filtered off, dried in vacuo and 9 g (100%) of 3-(4-fluorophenyl)-1H-pyrazol-5-ol are obtained as white solid.

Source