General Papers ARKIVOC 2016 (iv) 184-192 Page 184 © ARKAT-USA, Inc A facile one-pot synthesis of novel 1-substituted 2-(8-hydroxyquinolin-5-yl)-1,5,6,7-tetrahydro-6,6-dimethyl- 4H-indol-4-one derivatives Shawkat Abdel-Mohsen* and Talaat El-Emary Chemistry Department, Faculty of Science, Assiut University, Assiut, 71516, Egypt E-mail: shawk662001@yahoo.com DOI: http://dx.doi.org/10.3998/ark.5550190.p009.602 Abstract A green and efficient method for the synthesis of novel 5-(N-substituted indol-2-yl)-8- hydroxyquinolines has been achieved in good to excellent yields by one-pot three-component Domino reaction of 5-chloroacetyl-8-hydroxyquinoline with amines and dimedone using DABCO as a basic catalyst in ethanol under reflux conditions. The products were characterized by 1 H NMR, 13 C NMR, IR, and MS spectra. Keywords: One-pot reactions, quinolines, indol-4-ones, DABCO Introduction Multi-component reactions have emerged as a valuable tool in the context of modern combinatorial synthesis. Moreover, one-pot multi-component condensation reactions, due to their productivity, facile execution and simple reaction profile, are one of the important strategies in multi-component reactions, which have expanded rapidly in organic chemistry. 1-4 It is found in the recent literature that several indole derivatives are reported to possess a wide variety of biological properties, e.g. CNS depressant, 5 anti-inflammatory and analgesic, 6 antiviral, 7 anthelmintic, 8 antibacterial, 9 anticonvulsant, 10 cardiovascular, 11 and antihypertensive activity. 12 In recent years, 1,4-diazabicyclo[2.2.2]octane (DABCO) has emerged as a promoter for various organic reactions. 13–17 DABCO is an organic base that can act as a nucleophile. In view of this, and as part of our work on multi-component reactions, 18–22 we here report a simple, practical, and generally three-component reaction for the synthesis of novel indole derivatives by one-pot three-component reaction of 5-chloroacetyl-8-hydroxyquinoline, alkyl-, aryl- and heteroaryl-amines, and dimedone; the reaction is catalyzed by DABCO.