Efficient Synthesis and Characterization of Novel Substituted 3-Benzoylindolizine Analogues via the Cyclization of Aromatic Cycloimmoniumylides with Electrondeficient Alkenes

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.

Cite this article as:

Venugopala N. Katharigatta*, Chandrashekharappa Sandeep , Bhandary Subhrajyoti , Chopra Deepak , Khedr A. Mohammed , Aldhubiab E. Bandar , Attimarad Mahesh and Odhav Bharti , Efficient Synthesis and Characterization of Novel Substituted 3-Benzoylindolizine Analogues via the Cyclization of Aromatic Cycloimmoniumylides with Electrondeficient Alkenes, Current Organic Synthesis 2018; 15 (3) . https://dx.doi.org/10.2174/1570179414666171024155051