Orange Juice-Induced Remarkable Electrophilic Substitution Reaction of Indoles with Carbonyl Compounds

Introduction: The synthesis of bisindolylalkanes has been carried out for more than two decades using several catalysts. Method: In the present study, naturally available orange juice has been demonstrated to be an efficient green catalyst for the synthesis of bisindolylalkanes from the reaction of indoles with different carbonyl compounds. Result: In this one-step process, the products were obtained with excellent yield and in a short reaction time. Conclusion: This reaction-catalysed by orange juice is a new, inexpensive, and environmentfriendly synthetic procedure for the preparation of bisindolylalkanes.