Title:Efficient Synthesis and Characterization of Novel Substituted 3-Benzoylindolizine Analogues via the Cyclization of Aromatic Cycloimmoniumylides with Electrondeficient Alkenes
Volume: 15
Issue: 3
Author(s): Katharigatta N. Venugopala*, Sandeep Chandrashekharappa, Subhrajyoti Bhandary, Deepak Chopra, Mohammed A. Khedr, Bandar E. Aldhubiab, Mahesh Attimarad and Bharti Odhav
Affiliation:
- Department of Pharmaceutical Sciences, College of Clinical Pharmacy, King Faisal University, Al-Ahsa 31982,Saudi Arabia
Keywords:
Indolizines, chromium(IV)oxide, dehydrogenation, electron-deficient alkenes, synthesis, characterization, pharmacological property,
single crystal X-ray studies.
Abstract: Background: Indolizine pharmacophore is known to exhibit various promising pharmacological
properties such as analgesic, anticancer, antihistaminic, antidiabetic, anti-inflammatory, antileishmanic, antimicrobial,
antimutagenic, antioxidant, antitubercular, antiviral, larvicidal and herbicidal activities.
Objective: In the present investigation, it was envisaged to synthesize a series of novel ethyl-7-substituted-3-(4-
substituted benzoyl)-2-substituted indolizine-1-carboxylates by employing chromium(IV)oxide as dehydrogenating
agent with triethylamine combination.
Method: Synthesis of a series of proposed polysubstituted indolizines by employing chromium(IV)oxide as
dehydrogenating agent with triethylamine combination. Final compounds were characterized by spectroscopic
techniques viz fourier-transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, liquid chromatography-
mass spectrometry, elemental analysis and selected title compound diethyl-3-(4-
cyanobenzoyl)indolizine-1,2-dicarboxylate by single crystal X-ray method.
Results: Aromatic cycloimmoniumylides undergo smooth cyclization with electron-deficient alkenes in the
presence of triethylamine and DMF at room temperature to afford intermediates ethyl 7-substituted-2-
substituted-3-(4-substituted benzoyl)-1,2,3,8a-tetrahydroindolizine-1-carboxylates, which on dehydrogenation
with chromium(IV)oxide to obtain the title compounds ethyl-7-substituted-3-(4-substituted benzoyl)-2-
substituted indolizine-1-carboxylates.
Conclusion: The research was focused on developing an efficient protocol for the synthesis of a novel series of
ethyl 3-substituted benzoyl-7-substituted-2-substituted indolizine-1-carboxylates with suitable pharmacological
properties in good to excellent yields.
