Reactions with Hydrazonoyl Halides 42¹: Synthesis of Some New 2,3-Dihydro-1,3,4thiadiazoles, 2,3-Dihydro-1,3,4-selenadiazoles and Triazolino[, ]pyrimidines

Reaction with Hydrazonoyl Halides 64: Synthesis of Some New Triazolino[4,3‐a]pyrimidines, 1,3,4‐Thiadiazoles, and 5‐Arylazothiazoles

“…Treatment of 2‐(2‐phenylhydrazono)‐1‐(5‐bromobenzofuran‐2‐yl)‐2‐chloroethanone ( 4 ) with ethyl 4‐methyl‐6‐phenyl‐2‐thioxo‐1,3,6‐trihydropyrimidine‐5‐carboxylate ( 5a ) in chloroform and triethylamine gave ethyl 1,5‐dihydro‐3‐(5‐bromobenzofuran‐2‐oyl)‐7‐dimethyl‐1,5‐diphenyl‐[1,2,4]triazolo[4,3‐ a ]pyrimidine‐6‐carboxylate ( 9a ; Scheme ). The structure of 9a was elucidated on the basis of both elemental analysis and spectral data as well as alternative synthesis.…”

Ultrasound mediated synthesis of 2-amino-1,3-selenazoles derived from Fmoc/Boc/Z-α-amino acids

“…23 1,3,4-Selenadiazoles have been prepared by the reaction of potassium selenocyanate with hydazonoyl bromide. 24 Oxidation of aryl selenoamides with N-bromosuccinimide and iodine yielded 1,2,4-selenadiazoles. 25 Some of the disadvantages such as basic conditions, longer reaction duration and low yields limit the applicability of these methods.…”