Efficient access to some new pyrimidine derivatives and their antimicrobial evaluation

Abstract

1-[4-(3-Hydroxyphenyl)-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidin-5-yl]ethanone (1) was used as a precursor for heterocyclic synthesis. Condensation of compound 1 with monochloroacetic acid and benzaldehyde gave thiazolopyrimidine 2 which in turn underwent cyclization with malononitrile dimmer to afford malononitrile derivative 3. Also, the reaction of compound 1 with benzaldehyde under a basic condition produced chalcone 4. Chalcone 4 can be used as a key intermediate for further preparation of heterocyclic compounds. In addition, compound 1 was allowed to react with malononitrile dimmer and/or ethyl chloroacetate to give pyrimidines 8 and 9, respectively. Alkylation of compound 8 with ethyl chloroacetate afforded S-alkylated product 10 which was treated with hydrazine hydrate to yield the hydrazino derivative 11. Alternative synthesis of compound 10 was taken place through reaction of compound 9 with malononitrile dimmer. The biological activity of the synthesized compounds was investigated. Compounds 1, 4, 5, and 8 recorded high activities against Gram positive bacteria (S. aureus). Structures of the new synthesized compounds were elucidated by elemental analysis and spectral data.