The research work is carried out the investigation of reaction mechanism on the new route for the synthesis of various indole derivatives. Thus in the present work, I trace out the possibility of achieving various types of indole derivatives by employing various lewis acids, particularly bismuth nitrate, protic acids (nitro derivatives of phthalic acids) and antimony (III) trichloride were investigated. Beside this i also proposed the possibility of employing a three component one pot reaction, in which three species come together and react to generate the spirooxindoles and Tryptophan analogues in single step and these represents the greatest and efficient protocols for the synthesis of various indole compounds.