Ethyl 1-benzyl-2-(4-methylphenyl)-1h-pyrrolo[2,3-b]quinoxaline-3-carboxylate and ethyl 6,7-dimethyl-1,2- diphenyl-1h-pyrrolo[2,3-b]quinoxaline-3-carboxylate: synthesis and study on nuclear magnetic resonance spectroscopy
Year: 2025
Type: article
Abstract: Synthetic pyrrolo[2,3-b]quinoxalines have been confirmed to possess valuable biological activities and pharmacokinetic properties. However, the presence of heavy metal catalysts in synthesizing these heterocycles has restricted the application of those methods in pharmaceutical manufacturing. In this study, two pyrrolo[2,3-b]quinoxalines have been synthesized via the nucleophilic addition reaction between 1,5-disubstituted-4-ethoxycarbonyl-3-hydroxy-3-pyrrolin-2-ones and o-phenylenediamine or 4,5-dimethyl-o-phenylenediamine as nucleophiles in glacial acetic acid. In the acidic medium of acetic acid, 1,5-disubstituted-4-ethoxycarbonyl-3-hydroxy-3-pyrroline-2-ones could be tautomerized to keto tautomers, also known as 2,3-dioxopyrrolidine derivatives. More importantly, the structure of two desired pyrrolo[2,3-b]quinoxalines has been approved via nuclear magnetic resonance spectroscopy (1D NMR, 2D NMR) and high-resolution mass spectrometry (HRMS).
Authors: Vo Viet Dai, Bui Bich Loc, Nguyen Tran Nguyen
Institution: Trường Đại học Sư phạm – Đại học Đà Nẵng
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4411217435