Regioselectivity was examined of reactions between nine 3(5)-aminopyrazoles and 2-acetylcyclopentanone and 2-acetylcyclohexanone under various conditions. A series of cyclopenta[e]pyrazolo-[1,5-a]pyrimidines was obtained. The highest regioselectivity of the reaction was observed in alcohol at 20°С in the presence of a catalytic quantity of trifl uoroacetic acid. The regiostructure of compounds was established by 1Н and 13С NMR spectroscopy.