A simple, novel and suitable method has been developed for the one step synthesis series of 3-substituted imino- 5-[2-isobutoxy-5-(4-methyl-5-carboxy-1,3-thiazo-2-yl)-phenylformamidino]-amino-1,2,4-dithiazoles(VIa-f)was carried out by oxidative cyclisation of 2-(3-substituted-2,4-dithiobiureto-formamidino-4-isobutoxyphenyl)-4-methyl-5-carboxy- 1,3-thiazoles (Va-f) by making use of liquid bromine in chloroform medium as an oxidative cyclising agent.