On the basis of the Zaleplon structure, novel pyrazolo[l,5-a]pyrimidines were designed and prepared for studies on their hypnotic activity. This paper reported the synthesis of twelve new 5-methyl-7-substituted-pyrazolo[1,5-a]pyrimidine-3-carbonitrile derivatives by using simple starting materials such as propane dinitrile and triethyl orthoformate. The structures of the derived target compounds were confirmed by their IR and 1H-NMR spectroscopic data. The preliminary pharmacological evaluations indicated that some compounds showed hypnotic activity, while derivative 1c was the most polent one. On the basis of the Zaleplon structure, novel pyrazolo [l, 5-a] pyrimidines were designed and prepared for studies on their hypnotic activity. This paper reported the synthesis of twelve new 5-methyl-7-substituted-pyrazolo [1,5 -a] pyrimidine-3-carbonitrile derivatives by using simple starting materials such as propane dinitrile and triethyl orthoformate. The structures of the derived target compounds were confirmed by their IR and 1H-NMR spectroscopic data. The preliminary pharmacological evaluations indicating that some compounds showed hypnotic activity, while derivative 1c was the most polent one.