Molecules | |
Microwave Assisted Synthesis and Unusual Coupling of Some Novel Pyrido[3,2-f][1,4]thiazepines | |
Rasha M. Faty1  Mohamed M. Youssef1  | |
[1] 1Department of Chemistry, Faculty of Science, Cairo University, Egypt 2Department of Chemistry, Faculty of Science, Fayoum University, Egypt †Current address: Department of Chemistry, Faculty of Science, Taif University, Saudi Arabia. | |
关键词: microwave; monothiomalonamide; pyridinecarboxamide; pyridothiazepines; coupling; | |
DOI : 10.3390/molecules16064549 | |
来源: mdpi | |
【 摘 要 】
3-Amino-3-thioxopropanamide (1) reacted with ethyl acetoacetate to form 6-hydroxy-4-methyl-2-thioxo-2,3-dihydropyridine-3-carboxamide (2), which reacted with α-haloketones 3 to produce 2,3-disubstituted-8-hydroxy-6-methyl-2H,5H-pyrido[3,2-f]-[1,4]thiazepin-5-ones 4a-c. Benzoylation of 4c led to the formation of the dibenzoate derivative 9. Compounds 4a-c could be prepared stepwise through the formation of S-alkylated derivatives 10a-c. Compounds 2, 4a-c, 9 and 10a-c were prepared using microwave as a source of heat, and gave better yields in shorter times than those achieved by traditional methods. Coupling of 4a-c with arenediazonium chlorides proceeded unusually to give the 6-hydroxy-4-methyl-2-(arylazo)thieno[2,3-b]pyridin-3(2H)-one ring contraction products 14. Structures of the newly synthesized compounds were proven by spectral and chemical methods.
【 授权许可】
CC BY
This is an open access article distributed under the Creative Commons Attribution License (CC BY) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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