Synthesis of pyrimido[4,5- b ]quinolindiones and formylation: ultrasonically assisted reactions.

Ultrasound-assisted synthesis of pyrimido‌quinolindione derivatives via a multicomponent reaction and subsequent formylation with Vilsmeier-Haack reagent were performed. Compounds were prepared by a one-pot method from aminopyrimidinones, dimedone and aromatic aldehydes through a Mannich-type reaction sequence, and then functionalized under ultrasound irradiation and Vilsmeier-Haack conditions to give β-chlorovinylaldehyde products. Ultrasonically assisted reactions, experimental simplicity, good yields without using metallic catalysts and the control of hazardous material release are features of this simple procedure.