Carbamate (3a), amides (8b), (8d), and (8g) exhibited high activity against all the tested microorganisms, semicarbazone (6d) was completely inactive.
Sequential hydrazinolysis of carbamate (3e) and condensation with a variety of aldehydes and ketones (5a-d) afforded the corresponding semicarbazones (6a-d).
General procedures for synthesis of semicarbazones (6a-d)
This semicarbazide was a good candidate to prepare novel semicarbazones (6a-d) incorporating thiazole ring by condensation with different aldehydes and ketones (5a-d) namely, p-chlorobenzaldehyde, p-hydroxybenzaldehyde, cyclopentanone and cycloheptanone in ethanol containing catalytic amount of glacial acetic acid Scheme-1.
A simple and general method has been developed for the synthesis of various Schiff bases (oximes, hydrazones, semicarbazones and thiosemicarbazones) derived from 5-acyl-1,2,4- triazines.
Keywords: Oximes of 5-acyl-1,2,4-triazines, Hydrazones of 5-acyl-1,2,4-triazines, Thiosemicarbazones and Semicarbazones of 5-acyl-1,2,4-triazines, Antiviral activity, Schiff base.
A series of new Schiff bases (oximes, hydrazones, semicarbazones and thiosemicarbazones) derived from 5-acyl-1,2,4-triazines were synthesized in order to evaluate their biological activities.