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.
Funding
The financial resources, materials and reagents for laboratory work were granted by Universidad del Atlántico, and the financial resources, inputs, and technical support to collect the spectra were granted by Universidad del Valle.