Oxidation of aldehyde semicarbazones with lead dioxide: Application to the syntheses of 2??amino??1, 3, 4??oxadiazoles and 2, 4??dihydro??1, 2, 4??triazol??3??ones

TH Nguyen, R Milcent, G Barbier

Index: Nguyen, Thu-Huong; Milcent, Rene; Barbier, Geo Journal of Heterocyclic Chemistry, 1985 , vol. 22, p. 1383 - 1388

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Citation Number: 15

Abstract

Abstract The oxidation of aldehyde semicarbazones with lead dioxide in acid media was effected. The 4, 4-disubstituted semicarbazones of aromatic aldehydes afford 2-amino-1, 3, 4-oxadiazole derivatives. The 2, 4-disubstituted semicarbazones give 2, 4-dihydro-1, 2, 4- triazol-3-ones, often in higher yields than the known methods. The mechanisms for the formation of these compounds are proposed.