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441.
The reaction of 3-mercapto-4-arylideneamino-1,2,4-triazoles 2b-d , 3a-d with ethyl bromoacetate and/or phenacyl bromide in hot DMF and triethylamine affords the stereochemically pure 7-acyl-6-aryl-6,7-dihydro-5H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines 4b-d , 5a-d , 6b , d in which the consecutive hydrogen atoms N(5)H-C(6)H-C(7)H are cis to each other. This stereochemistry was determined by 1H NMR spectroscopy and confirmed by comparison with the spectrum of 3,6-diphenyl-6,7-dihydro-5H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine 10 . The latter was prepared by NaBH4 reduction of 3,6-diphenyl-5H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine 9 . The reported reactions offer two interesting stereospecific syntheses of the condensed heterocyclic compounds. 相似文献
442.
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. 相似文献
443.
444.
Aminoacetonitrile ( 1 ) reacted with acetamidinium chloride to give 4‐aminoimidazole ( 4 ), which reacted with DMFDMA to yield imidazole derivative 7 and with benzylidinemalononitrile and ethoxymethylene malononitrile to give imidazo[1,5‐a]pyrimidine derivatives 12 and 15 . Compound 1 reacted with β‐crotononitrile to yield pyridine derivative 20 . Imidazo[1,2‐a]pyridine derivative 23 could be obtained via the reaction of 20 with DMFDMA. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:503–508, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10178 相似文献
445.
Asmaa Ahmed Mohamed Elsakka Nabil Elminshawy Ayman Mohamed Senthilarasu Sundaram 《Chemical record (New York, N.Y.)》2023,23(12):e202300229
In recent years, floating photovoltaic (FPV) technologies have gained more importance as a key source of clean energy, particularly in the context of providing sustainable energy to buildings. The rise of land scarcity and the need to reduce carbon emissions have made FPV systems a cost-effective solution for generating electricity. This review article aims to explore the rapidly growing trend of floating PV systems, which can be a practical solution for regions with limited land areas. The article discusses the structure of the PV modules used in FPV plants and key factors that affect site suitability choice. Moreover, the article presents various techniques for cooling and cleaning FPV to keep optimal performance and discusses feasible trends and prospects for the technology. Finally, this paper proposes the potential integration of FPV systems with other technologies to enhance energy generation efficiency and discusses other research aimed at the advancement of the technology. By examining the various features of FPV systems, this review article contributes to understanding the advantages and challenges associated with using this sustainable energy technology in different regional contexts. 相似文献