Electronic supplementary material from “Synthesis of pyrimido[4,5-b]quinoline -4,6-diones and formylation: Ultrasonically assisted reactions”.

Ultrasound-assisted synthesis of 5-aryl-tetrahydropyrimido[4,5-b]quinolindione derivatives 4 and 5 via a multicomponent reaction and subsequent formylation with Vilsmeier-Haack reagent were performed. Compounds were prepared by a one-pot method from 6-amino-3-methyl-2-(methylthio)pyrimidin-4(3H)-one or 6-amino-2-methoxy-3-methylpyrimidin-4(3H)-one, 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.