Synthesis, Characterization and Biological Screening of Some Novel Sulphur Bridged Pyrazole, Thiazole, Coumarin and Pyrimidine Derivatives

Abstract

Pyrimidine-2-thiol derivative (1) reacted with ethyl 4-chloroacetoacetate in the presence of potassium carbonate to give thioacetoacetate derivative (3). The later compound upon treatment with hydrazine derivatives gave pyrazolone derivatives (4a-e). The reaction of compound 3 with salicylaldehyde or 2-hydroxaynaphthaldehyde afforded coumarin derivatives (5a,b), respectively. Also, the reaction of thioacetoacetate derivative (3) with either urea or thiourea gave the corresponding pyrimidine derivatives (6a,b). Compound 3 reacted with diazonium salts to give diazo compounds 7a,b. Compounds 8a-d were obtained through the reaction of 6b with different halogenated compounds, while the reaction of 6b with hydrazine hydrate afforded hydrazine derivative (9). Condensation of the later with 4-methoxybenzaldehyde gave 10. Treatment of pyrazolone derivative 4b with different aldehydes afforded compounds 15a,b and 16. While coupling with 4-tolyldiazonium chloride gave compound 17. Finally, the reaction of pyrazole derivative 4c with different halogenated compounds afforded 18, 22, 24 and 26. The structures of the newly synthesized compounds were confirmed by elemental analysis and spectral data. The newly synthesized compounds were also screened for their antimicrobial activity.