Abstract

M. E. Abdel Fattah¹*, A. H. Atta¹, I. I. Abdel Gawad²** and S. M. Mina²**

7-Amino-4-oxo- 5-aryl-2 thioxo-1, 3, 4, 5-tetrahydro-2H-pyrano [2-3, d] pyrimidine-6-carbonitrile 3a-c were prepared via the reaction of thiobarbituric acid with p-arylidine malononitrile yielded comound 1a-c, followed by heatingof 1a-c in the presence of ethanol and triethylamine. Compound 3a-c were also prepared by treatment of areylidenethiobarbituric acid 2a-c with malononitrile in the presence of triethylamine as a catalyst throught Michael's addition of melanonitrile on the exocyclic double bond of arylidene thiobarbituric acid followed by cyclization. Treatment of 2- thiobarbituric acid with triethylorthoformate afforded compound 5-diethoxy-methylene-2-thiobarbituric acid 4. Reaction of 4 with malononitrile in ethanol and in resence of triethylamine as a catalyst gave compound 3-(4,6-Dioxo-2-thioxo-hexahydro-pyrimidine-5-yl)-ethoxyacrylonitrile 5. Treatment of thiobarbituric acid with CS2 followed by the reaction with o-phenylenediamine afforded compound 6 (Scheme 1). Compounds 7a-c were prepared via the reaction of compound 3a-c with triethyl orthoformate in the resence of acetic anhydride. Reaction of 7a-c with hydrazine hydrate and aniline gave compound 8 and 9 resectively. Treatment of 3a- with malononitrile, benzaldehyde, phenylisothiocyanate and CS2 yielded compound 10, 11, 12 and 13 respectively. Condensation of compound 13 with o-phenylenediamine gave 14. Acetylation of 3a with acetic anhydride and acetyl chloride yielded compounds 15, 16 respectively. Compound 17 was obtained by reaction of 3a with formic acid. (Scheme, 2). The structure of the synthesized compounds were established from their elemental analysis as well as spectroscopic data. The synthesized compounds were tested towards some microorganisms (Fungi, bacteria and yeast) and some of them were found to have antimicrobial activities.

Synthesis; antimicrobial activity; pyrimidine derivatives

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