Cyclohexylhydrazine hydrochloride → Ethyl 1-cyclohexyl-5-(4-benzyloxyphenyl)-1H-pyrazole-3-carboxylate

Participants

Reaction Steps

The butenoate 1.2 (5.00 g, 15.3 mmol) and cyclohexylhydrazine hydrochloride (2.77 g, 18.4 mmol) were heated at refluxed in EtOH (60 ml) for 2 h. Concentration in vacuo resulted in formation of a solid which was suspended in EtOAc and filtered through a 1″ pad of SiO2, elution with ethyl acetate. The filtrate was concentrated to afford 6.10 g (98%) of the desired pyrazole ester 1.3. MS (ESI) 405.4 (M+H+).

Provenance & Evidence