1-Cycloalkyl-2-propene-1-ones were synthesized by electrophilic addition of cycloalkanecarboxylic acid chlorides and its mono- and dichloride-substituted derivatives to ethylene in the presence of an AlCl₃ catalyst at a temperature of –10 ÷ –15⁰C in a dichloroethane medium. The resulting vinyl ketones were converted by chlorination in CCl₄ at  –5⁰C to the corresponding 1-cycloalkyl-2,3-dichloro-1-propanones, which form 1-R^´-3-cycloalkylpyrazoles with hydrazine and phenylhydrazine in ethanol or toluene. The structure of the obtained pyrazoles was confirmed by the data of IR and H¹NMR spectra and the determination of physical-chemical constants. Thus, preparative methods for the synthesis of 3- and 1,3-pyrazole derivatives have been developed for the first time

doi.org/10.32737/0005-2531-2022-4-89-94