An expeditious synthetic approach towards the synthesis of Bis-Schiff bases (aldazines) using ultrasound

•An ultrasound-assisted expeditious synthetic approach.•The advantages of this methodology are higher selectivity, simplicity, and shorter reaction time.•Environmental friendly.

Aldazines (Bis-Schiff bases) 1–24 were synthesized using aromatic aldehydes (heterocyclic and benzaldehydes) and hydrazine hydrate under reflux using conventional heating and/or via ultrasound irradiation using BiCl3 as catalyst. Ultrasonication conditions with cat. BiCl3 proved to be an effective, environmentally friendly synthetic procedure. This methodology is robust in the presence of electron donating and electron withdrawing groups affording desired products with high yields (>95%) in just a couple of minutes vs. hours using conventional heating.