A simple and Novel improved process for the preparation of pure Sumatriptan and Rizatriptan, the cyclisation of indole ring by the using of ortho phosphoric acid. The present work describes the detection, origin, synthesis, characterization and providing a commercial method to synthesize Sumatriptan and Rizatriptan. The procedure developed has several advantages such as mild reaction conditions, convenient operations and easily obtained materials. The synthetic method is suitable for industrial manufacture.