Cavitational chemistry: A mild and efficient multi-component synthesis of amidoalkyl-2-naphthols using reusable silica chloride as catalyst under sonic conditions

An efficient and direct procedure for the synthesis of amidoalkyl-2-naphthol derivatives has been described. The process employs a three-component cyclocondensation reaction in one-pot using β-naphthol, aromatic aldehyde and acetamide or benzamide in the presence of silica chloride accelerated by ultrasound giving the product in excellent yield in very short duration.

Research highlights
► Ultrasound assisted synthesis of amidoalkyl-2-naphthols.
► Aromatic aldehydes and 2-naphthol give o-quinone methides under sonic condition.
► Addition of amides to o-quinone methides give amidoalkyl-2-naphthols.
► Application of a heterogeneous and reusable catalyst – silica chloride under ultrasonic condition.
► Ultrasound enhances the rate and increases the yield of the products.