A Simple Synthesis and Antimicrobial Activity of Sulfur-containing Poly-condensed Heterocyclic Derivatives from 1,3-benzothiazole

A novel series of 7-amino-5-aryl-6-(benzothiazol-2-yl)-2-thioxopyrido{2,3-d}pyrimidin-4-one derivatives was prepared and their reactivity towards some reagents was studied. Transformations of aromatic aldehydes, halogens and some hydrazonoyl chlorides towards the corresponding poly-condensed heterocyclic compounds, such as 8-amino-7-(benzothiazol- 2-yl)-{1,3}thiazolo{4,5-a}pyrido{2,3-d}pyrimidine-3,5-diones, 3,9-diarylisoazolo{5´,4´:4,5}thiazolo-{3,2-a}pyrido{ 2,3-d}pyrimidin-10-ones and 1,6-diaryl and 3-aryl- or 3-acetyl- or 3-ethylcarboxylate- derivatives of 7-(benzothiazol- 2-yl)-pyrido{2,3-d}{1,2,4}triazolo{4,5-a}pyrimidin-5-ones were investigated. Compounds synthesized were screened in vitro for their antimicrobial activity against a variety of bacterial and fungal agents.