N,N-dimethyl-10H-phenothiazine-2-sulfonamide is the very important intermediate of Pipothiazine which is the representative drug of anti-psychotic disorders.In this study, o-bromoaniline was condensed and hydrolysesed , then condensed by N,N-dimethyl-4-chloro-3-nitrobenzenesulfonamide,and reduced by zinc dust,after via Ullmann reaction to give the final target compounds. The effects of different solvent/base、temperature on the yield of condensation,reducing agent proportion on the yield of the reduction,and catalyst agent proportion、reaction temperature and reaction time on the yield of the Ullmann reaction were studied.After 5 steps,the total yield could reach up to 45.5%, the reaction condition was mild,and easily to be treated,the structure of the targer compound was confirmed by means of ESI-MS and 1HNMR.