Antidepressant, Phenothiazine, QSAR, Antidepressants are the drugs used to treat depression thereby elevates mood and modifies the behavior. The main aims in the development of new antidepressants were greater efficacy, absence of side effects, lack of toxicity in over dose and earlier onset of action. In this study, a series of novel substituted phenothiazine was synthesized and evaluated for antidepressant activity by using or forced swim test (FST). Our synthetic route started from substituted aniline which was reacted with cyclohexanone. The later compound with sulfur powder and iodine led to the formation of the title compounds. Total 12 phenothiazine derivatives, A1 to A12 were tested for antidepressant activity by using or forced swim test (FST). All the synthesized compounds were subjected to antidepressant activity study on Sprague-Dawley rats by despair swim test. Imipramine was used as standard control. The results showed that all the compounds showed antidepressant activity. Among them two compounds, A3 and A6 showed significant antidepressant activity comparing with standard control imipramine. | QSAR and anti-depressant studies of some novel phenothiazine derivatives