Synthesis of unsymmetrical 3,5-disubstituted 1,2,4-triazole derivatives with their pKa values

Abstract

Acylhydrazones (2a-b) were synthesized by the condensation of iminoester hydrochlorides (1a-b) with benzhydrazide. the treatment of acylhydrazones With hydrazine hydrate afforded 4-amino-4H-1,2,4-triazoles. (3a-b). 4-Benzylidenamino-4H-1,2,4-triazole derivatives (4a-f) to be synthesized by treatment of compounds (3a-b) with benzaldehydes. Compounds (4a-f) were reduced with NaBH4 to afford the corresponding 4benzylamino-4H-1,2,4-triazole derivatives (4a-f). All synthesized compounds Were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as isopropyl alcohol, tert-butyl alcohol, acetonitrile and N,N-dimethylformamide and the half-neutralization potential values and the corresponding pKa values were determined for all cases.