Single step synthesis of (2E)-1-[4-(3-substitutedimino-1,2,4-dithiazolo)aminophenyl]-3-(3,4-dimethoxyphenyl)prop- 2-en-1-one (II-e) was carried out by oxidative cyclisation of (2E)-1-[4-(5-substituted-2,4-dithiobiureto)phenyl]-3- (3,4-dimethoxyphenyl)prop-2-en-1-one (Ia-e) using liquid bromine in chloroform medium as an oxidizing agent. The products were isolated, characterized and justified on the basis of conventional elemental analysis, chemical characteristics and spectral studies.