Ultrasound Assisted and Aluminized Polyborate Prompted Green and Efficient One Pot Protocol for the Synthesis of Hexahydroquinolines

The present work reports ultrasound assisted and aluminized polyborate prompted green and efficient protocol for one pot four component Hantzsch condensation of aromatic aldehydes, dimedone, ethylcyanoacetate, and ammonium acetate to give hexahydroquinoline derivatives in ethanol:water (1:1) at room temperature. The key features of this protocol are sonochemical synthesis, environmental benign, short reaction time, recyclable catalyst, simple procedure, clean reaction, excellent product yields, and non-column purification. Additional importance of this method is an application of eco-sustainable aluminized polyborate as a catalyst, which is simply synthesized from easily available boric acid and aluminum trichloride. The catalyst was characterized by FT-IR, XRD, EDAX, and SEM techniques.