A novel one-pot two step tandem reaction for the synthesis of indolizine-1-carbonitrile derivatives (5a-i) was identified. The route comprises 1,3-dipolar cycloaddition reaction of aromatic aldehyde derivatives (1a-i), malononitrile (2) and 1-(2-(4-bromophenyl)-2-oxoethyl)-2-chloropyridin-1-ium (4) under ultrasound irradiation at room temperature in the presence of triethylamine at acetonitrile...