616235-94-0Relevant articles and documents
Aiding the versatility of simple ammonium ionic liquids by the synthesis of bioactive 1,2,3,4-tetrahydropyrimidine, 2-aminothiazole and quinazolinone derivatives
Kakati, Praachi,Singh, Preeti,Yadav, Priyanka,Awasthi, Satish Kumar
, p. 6724 - 6738 (2021/04/22)
Simple ammonium ionic liquids [ILs] are efficient, green, environmentally friendly catalysts in promoting the Biginelli condensation reaction, Hantzsch reaction and Niementowski reaction to afford 1,2,3,4-tetrahydropyrimidine, 2-aminothiazole and quinazolinone derivatives respectively by eliminating the need for harmful volatile organic solvents. These [ILs] are air and water stable, easy to prepare and cost-effective. The effects of the anions and cations present in [IL] on reactions were investigated. The results clearly indicated that the Biginelli condensation reaction, Hantzsch reaction and Niementowski reaction were heavily influenced by the acidity of [IL], and among various ammonium ionic liquids, [Et3NH][HSO4] showed the best catalytic activity. Furthermore, [IL] could be easily separated and reused with a slight loss of its activity. This technique provided a good alternative way for the industrial synthesis of 1,2,3,4-tetrahydropyrimidinones, 2-aminothiazoles and quinazolinones. The present processes are eco-friendly methods for the synthesis of these derivatives authenticated by several green parameters, namely,E-factor, process mass intensity, reaction mass efficiency, atom economy, and carbon efficiency.
Sustainable methine sources for the synthesis of heterocycles under metal- and peroxide-free conditions
Senadi, Gopal Chandru,Kudale, Vishal Suresh,Wang, Jeh-Jeng
, p. 979 - 985 (2019/03/12)
Alcohols and ethers were identified as sustainable methine sources for synthesizing quinazolinone and benzimidazole derivatives using a combination of TsOH·H2O/O2 and appropriate bis-nucleophiles for the first time. Deuterium labeling studies clearly proved that the C2 hydrogen of the synthesized heterocycles came from the methine source. These unique reaction conditions were successfully applied to the synthesis of echinozolinone (2e′), 2f′ (a common precursor of rutaecarpine and (±) evodiamine), and dimedazole (6d). Notable features of this method include its low toxicity, use of commercial feedstocks as substrates, low cost, broad functional group tolerance and suitability for a wide range of bis-nucleophilic starting materials.
Copper-catalyzed radical methylation/C-H amination/oxidation cascade for the synthesis of quinazolinones
Bao, Yajie,Yan, Yizhe,Xu, Kun,Su, Jihu,Zha, Zhenggen,Wang, Zhiyong
, p. 4736 - 4742 (2015/05/13)
A copper-catalyzed radical methylation/sp3 C-H amination/oxidation reaction for the facile synthesis of quinazolinone was developed. In this cascade reaction, dicumyl peroxide acts not only as a useful oxidant but also as an efficient methyl source. Notably, a methyl radical, generated from peroxide, was confirmed by electron paramagnetic resonance for the first time.