In this work the alkylation of 2-ethylsulfanyl -5-methoxy-4(3H)-pyrimidinone with 4-substituted ω-bromoacetophenones, ethyl 2-bromoalkanoates and 1-bromomethyl-o-carborane was investigated. It was found that reaction of title compounds in the presence of potassium carbonate in boiling acetonitrile yielded O-alkylated derivatives with small amount of N3- and N1-alkylation products. The proportion of O- and N-alkylated products varied depending on the nature of substituent in the 4th position of benzene ring. Alkylation of title compound with ethyl bromoethanoate led to mixture of O-, N3- and N1 alkylated derivatives, while the reaction with ethyl 2-bromopropanoate yielded only O-alkylated isomer. 2-Substituted 4-pyrimidinols with nido-carborane at the side chain were synthesized. The structure of synthesized compounds was confirmed by the data of IR, UV and 1H NMR spectra.

We report herein on the results of N- and O-alkylation of 5-cyano-2-methylsulfanyl-4(3H)- pyrimidinone with 4-substituted ω-bromoacetophenones. Synthesized N-(phenacyl)-4- pyrimidinones and 4-(phenacyloxy)pyrimidines with suitable substituents in pyrimidine ring are versatile synthons for the preparation of fused pyrimidine heterocycles. Chemical properties of new furo[2,3-d]pyrimidines were investigated. The structure of synthesized compounds was confirmed by data of 1H NMR, IR and UV spectra.