Hydrochloric Acid → 3-(Trifluoromethyl)pyrazole

Participants

Reaction Steps

2.71 kg of 1,1,1-trifluoro-4-methoxy-but-3-en-2-on, 2.44 kg of ethanol and 3.10 kg of water were charged into a reaction vessel. 20 ml of concentrated hydrochloric acid and 0.80 kg of hydrazine hydrate were successively added and the mixture was heated to reflux for 4 h. The mixtures was allowed to cool and neutralized by addition of 10% aqueous NaOH to about pH 4-5. Then the mixture was evaporated. Toluene was added and the mixture was again evaporated to yield 2 kg of raw 3-trifluoromethylpyrazole with a purity of >85%.

Provenance & Evidence