Diversified Aminohydantoins from Ureas and Thioureas Tethered to Amides
作者:Sukumar Bepary、In Kwon Youn、Hee-Jong Lim、Ge Hyeong Lee
DOI:10.1002/ejoc.201200025
日期:2012.5
Intramolecular cyclization of thioureas or ureastethered to amides afforded 2-iminohydantoins and 2-amino-1H-imidazol-4(5H)-ones in very high yields (87–100 %) regardless of the substituent (alkyls or aryls). This reaction proceeds through carbodiimides and iminium ions as intermediates. Among the reagents used to generate the carbodiimides, CBr4/Ph3P, CCl4/Ph3P, O,O′-bis(2′-pyridyl)thiocarbonate
DPT-Mediated Synthesis of 2-Aminoimidazolidin-4-ones from Thioureas Tethered to Amides
作者:Sukumar Bepary、In Kwon Youn、Hee-Jong Lim、Ge Hyeong Lee
DOI:10.1080/00397911.2013.827724
日期:2014.7.3
Abstract 2-Aminoimidazolidin-4-ones have been synthesized by using di-2-pyridyl thiocarbonate (DPT), taking the thioureastethered to amides as the starting materials. Both the primary amides and secondary amides have been subjected to this cyclization method and in general this simple and convenient method was found to ensure good to excellent yields (81–99%). GRAPHICAL ABSTRACT