Synthesis and Antimicrobial Evaluation of Some New Pyrazolo[1,5-a]pyrimidine and Pyrazolo[1,5-c]triazine Derivatives Containing Sulfathiazole Moiety.

A number of important fused heterocyclic systems have been prepared by the reaction of 4-((3,5-diamino-1H-pyrazol-4-yl)-diazenyl)-N-(thiazol-2-yl)-benzenesulfonamide with some bifunctional nucleophiles such as ethyl acetoacetate, acetylacetone or arylidenemalonononitrile derivatives to obtain pyrazolo[1,5-a]pyrimidine derivatives. The structures of the newly synthesized compounds were determined based on their IR, 1H and 13C NMR and mass spectroscopic data. Most of the compounds produced showed good antibacterial and antifungal activity.

Synthesis, Characterization and Cytotoxicity Evaluation of Some Novel Pyridine Derivatives.

Reaction of isonicotinaldehyde with 2-cyanoacetohydrazide afforded (E)-2-cyano-N'-(pyridin-4-ylmethylene)acetohydrazide (1). Compound 1 was used as the precursor for the synthesis of novel pyridine derivatives by reaction with different arylidene malononitriles, malononitrile and acetylacetone to give pyridine derivatives 5a-e, 6 and 7, respectively. 4,4'-Bipyridine derivatives 9a-d were synthesized by a three-component reaction of isonicotinaldehyde, 2-cyanoacetohydrazide and activated nitriles 8a-d.

Synthesis and Cytotoxic Activity of Some Novel Thieno[2,3-d:4,5-d']Dipyrimidine Derivatives.

Synthesis of some novel tricyclic compounds bearing thienodipyrimidine moiety by the reaction of ethyl 6-amino-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydrothieno[3,2-d]pyrimidine-7-carboxylate (1) with different types of aromatic amines to give the corresponding carboxamide derivatives 2-11, which cyclized with triethyl orthoformate in acetic anhydride to afford thieno[2,3-d:4,5-d']dipyrimidine derivatives 12-15 is described. Similarly, thieno[2,3-d:4,5-d']dipyrimidine derivative 17 was also prepared via the reaction of carboxamide derivative 2 with chloroacetyl chloride in chloroform to give thieno[3,2-d]pyrimidine-7-carboxamide derivative 16, followed by a cyclization in boiling acetic anhydride. The structure of these compounds was confirmed on the basis of their spectral and analytical data such as IR, 1H-NMR, 13C-NMR spectroscopy and mass spectral data.