Synthesis of 3-(phenylazo)-1,2,4-triazoles by a nucleophilic reaction of primary amines with 5-chloro-2,3-diphenyltetrazolium salt via mesoionic 2,3-diphenyltetrazolium-5-aminides

Abstract

SummaryThe reactions of a 5-chloro-2,3-diphenyltetrazolium salt with amines have been examined. In the presence of an inorganic base such as NaHCO3, primary and secondary amines undergo a nucleophilic substitution to give the corresponding 5-aminotetrazolium salts. When triethylamine is used as a base, primary amines give 3-phenylazo-1,2,4-triazoles. A plausible dual-path mechanism is proposed for the formation of the triazoles via Type B mesoionic tetrazolium-5-aminides.

Sustained release of hydrophilic drug from polyphosphazenes/poly(methyl methacrylate) based microspheres and their degradation study

“…It also reacts and converts into diethylamine. The convergence of TEA into diethylamine was confirmed by various researchers [44][45][46]. The presence of peaks at δ 1.16 and 3.07 showed the formation of diethylamine, as shown in Scheme 1 and Figure S1.…”

Synthesis of stable class 5 mesoionic benzo[c]tetrazolo[2,3-a]cinnolinium thiolate, dicyanomethylide, and amides

“…Type B, recently classified as class 5 (Scheme 1a bottom), 3 mesoionic compounds are known to undergo isomerization, 8,13 and their stability has been a major concern. Recently, Ramsden and Oziminski presented a detailed discussion of the equilibrium shown in Scheme 1c based on a computational study.…”