Open AccessScreening of Natural Deep Eutectic Solvents for Green Synthesis of 2-methyl-3-substituted Quinazolinones and Microwave-Assisted Synthesis of 3-aryl Quinazolinones in Ethanol
Author(s) -
Mario Komar,
Maja Molnar,
Anastazija Konjarević
Publication year - 2020
Publication title -
croatica chemica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.214
H-Index - 50
eISSN - 1334-417X
pISSN - 0011-1643
DOI - 10.5562/cca3597
Subject(s) - choline chloride , anthranilic acid , deep eutectic solvent , quinazolinone , chemistry , aryl , acetic anhydride , solvent , organic chemistry , ethanol , one pot synthesis , green chemistry , eutectic system , ionic liquid , catalysis , alkyl , alloy
In this study, two fast and efficient protocols for green synthesis of 3-substituted quinazolinones were perfomed. A synthesis of 2-methyl-3-substituted quinazolinones was performed in natural deep eutectic solvents, while 3-aryl quinazolinones were obtained by using microwave assisted synthesis. Benzoxazinone, which was used as an intermediate in the synthesis of 2-methyl-3-substituted quinazolinones, was prepared conventionally from anthranilic acid and acetic anhydride. In order to find the most appropriate synthetic path, twenty natural deep eutectic solvents were applied as a solvent in these syntheses. Choline chloride:urea (1 : 2) was found to be the most efficient solvent and was further used in the synthesis of 2-methyl quinazolinone derivatives (2–12). 3-Aryl quinazolinones (13–17), on the other hand, were synthesized in one-pot microwave-assisted reaction of anthranilic acid, different amines and trimethyl orthoformate. All compounds were synthesized in good to excellent yields, characterized by LC-MS/MS spectrometry and 1H- and 13C-NMR spectroscopy.