J. Looker, L. Wilson
Dec 1, 1965
Citations
0
Influential Citations
15
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
1,2,3-Thiadiazole-4-carboxylic acid (IV) has been synthesized by oxidation of 5-(2-furyl)-1,2,3-thiadiazole-4-carboxylic acid (IIb), and converted via the acid chloride (V) to the amide (VI), ethyl ester (VII) and azide (IX). Rearrangement of the azide (IX) in ethanol led to ethyl N-(1,2,3-thiadiazol-4-yl)carbamate (X) and in benzene or toluene to a complex substance, possibly N,N,N-tris-(1,2,3-thiadiazol-4-yl)-isocyanurate (XI). Ethyl 5-phenoxy-1,2,3-thiadiazole-4-carboxylate (XIII), prepared from ethyl (phenoxy-acetyl)diazoacetate (XII), has been converted to ethyl 5-formyl-1,2,3-thiadiazole-4-car-boxylate methyl phenyl acetal (XVI) via the α -halo ether (XIV). The acetal (XVI) underwent partial hydrolysis in dilute acid to yield ethyl 5-formyl-1,2,3-thiadiazole-4-car-boxylate phenyl hemiacetal (XVII) as an oil. Vacuum distillation of XVII gave ethyl 5-formyl-1,2,3-thiadiazole-4-carboxylate (XVIII) as an oil. The aldehyde XVIII, but not the hemiacetal XVII, formed a crystalline oxime (XIX) with hydroxylamine.