Present research work comprises, isomerisation of series of (2E)-1-[4-(2-ethylimino-4-substitutedimino)-1,3,5- dithiazino-6-yl) aminophenyl]-3-(3,4-dimethoxy phenyl)prop-2-en-1-one (Ia-e) were successfully carried using sodium bicarbonate in aqueous ethanol in to (2E)-1-[4-(2,4-dithio-3-ethyl-5-substituted-1,3,5-triazino-6-yl) aminophenyl]-3- (3,4-dimethoxyphenyl) prop-2-en-1-one (IIa-e). All the synthesized compounds were justified on the basis of chemical tests, elemental study and spectral characterization.