Phenothiazine is an organic compound and it is related to the thiazine class of heterocyclic compounds. A novel series of Phenothiazine derivatives were prepared by the reaction of Para amino benzoic acid with 3 different substituted anilines. All the compounds were characterized by melting point, UV, TLC, IR and C,H,N elemental analysis. The synthesis of 3 derivative compounds were prepared, those are 3 derivatives of substituted phenothiazine were prepared in scheme 1 from p-chloro benzoic acid aniline derivatives. All the compounds were structurally elucidated with physical and analytical methods. All the compounds evaluated with invitro anti inflammatory activity by protein denaturation method. The synthesized derivatives were screened for invitro anti-inflammatory activity. 5C Compound showed significant effect at 200-1000 µg/ml.