Synthesis of some substituted 1,3,4-oxadiazoles, thiadiazoles and 1,2,4-triazoles
ABSTRACT<br /> In this paper the synthesis of some substituted 1,3,4-oxadiazoles, 1,3,4-thiadiazoles and 1,2,4-triazoles is reported. Ethyl methacrylate was treated with hydrazine hydrate in ethanol to give the corresponding hydrazide (1). The hydrazide was converted to 1-acyl thiosemicarbazid...
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| Format: | Article |
| Language: | Arabic |
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College of Education for Pure Sciences
2009-06-01
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| Series: | مجلة التربية والعلم |
| Subjects: | |
| Online Access: | https://edusj.mosuljournals.com/article_57686_9cab6a19e0184b37ecb607fda0d4368f.pdf |
| Summary: | ABSTRACT<br /> In this paper the synthesis of some substituted 1,3,4-oxadiazoles, 1,3,4-thiadiazoles and 1,2,4-triazoles is reported. Ethyl methacrylate was treated with hydrazine hydrate in ethanol to give the corresponding hydrazide (1). The hydrazide was converted to 1-acyl thiosemicarbazide (2) byits reaction with ammonium thiocyanate, which was treated with sodium hydroxide solution and with concentrated sulfuric acid to give 5-substituted-1,2,4-triazoles-3-thiol (3) and 2-substituted-5-amino-1,3,4-thiadiazole (4) respectively. The acid hydrazide (1) was treated with benzaldehyde or substituted benzaldehyde to give hydrazones (7-12), the hydrazones were then cyclized with lead dioxide to 2-subtituted-5-phenyl 1,3,4-oxadiazole (14). The reaction of the hydrazide (1) with formic acid gave 1-formyl-2-acyl hydrazine (6) and the cyclization of (6) by phosphorus pentaoxide gave monosubstituted-1,3,4-oxadiazoles (13). Acid hydrazide (1) was treated with phenyl isothiocyanate to give substituted thiosemicarbazide (5). |
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| ISSN: | 1812-125X 2664-2530 |