2-Amino-5-(2-aryl-2H-1,2,3-triazol-4-yl)-1,3,4-thiadiazoles 2-4 have been synthesized by the reaction of 2-aryl-2H-1,2,3-triazole-4-carboxylic acids 1 with thiosemicarbazide. Their reaction with phenacyl (p-substituted phenacyl) bromides led to formation of the respective 6-aryl-2-(2-aryl-2H-1,2,3-triazol-4-yl)imidazo[2,1-b]-1,3,4-thiadiazoles 5. Reactivity of the latter fused ring towards reaction with different electrophilic reagents afforded the corresponding 5-substituted derivatives 6-8. The structure of the above compounds was confirmed from their spectral characteristics. Some of these compounds were found to possess slight to moderate activity against the microorganisms Staphylococcus aureus, Candida albicans, Pseudomonas aeruginosa, and Escherichia coli.
5-Aryl-2-phenylpyrazolo[1,5-c]pyrimidine-7(6H)-thiones have been synthesized by the reaction of 1,5-diaryl-4-pentyne-1,3-diones with thiosemicarbazide and their reactions were studied. The pyrazolopyrimidinethiones give with certain electrophiles the respective 3-substituted 7-thiones. Their oxidation affords the corresponding disulfide. Moreover, they can be converted to the corresponding pyrazolopyrimidinones on reaction with alkaline hydrogen peroxide. The structure of the above compounds was confirmed from their spectral characteristics.
A simple method for the synthesis of acetylenic β‐diketones is described. They can be cyclized to the corresponding 4H‐pyran‐4‐ones with acids. Their reaction with hydrazine hydrate gave pyrazole derivatives isomeric with those obtained from 4H‐pyran‐4‐ones. With hydroxyl‐amine hydrochloride in ethanol, 1‐hydroxy‐4‐pyridones are formed.
Thermal cyclization of 1,5‐diarylpent‐1‐yne‐3,5‐diones led to the formation of 2‐benzyliden‐5‐aryl‐3(2H) furanones as well as 2,6‐diaryl‐4H‐pyran‐4‐ones as minor products. The structure of the furanones was established from their ir, 1H nmr and mass spectral data. Their reaction with hydrazine hydrate gave pyrazole derivatives.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.