Heteropolyacid catalyzed formation of thioparabanic acid derivatives
作者:Alireza Samzadeh-Kermani
DOI:10.1007/s00706-016-1774-y
日期:2017.2
AbstractA heteropoly acid-catalyzed reaction between amines, ammonium thiocyanate, and oxalate esters is reported. This route turned out to be a useful method for the preparation of thioparabanic acidderivatives. Graphical abstract
Triton-B/CS2 system has been discussed. The protocol described is an easy, efficient, nature-friendly method using cheap, easily available, less toxic reagents at room temperature. The synthesis involves the reaction between substituted thiourea in toluene and oxalylchloride at room temperature using phase transfer catalyst Triton-B/CS2 system.
1,3-Acylumlagerungen bei der Cyclisierung von Thioharnstoffen mit Imidoylchloriden der Oxals�ure - Ein Zugang zu interessanten Thiocarbonylsystemen
作者:R. Beckert、M. Gruner
DOI:10.1002/prac.19923340711
日期:——
By cycloacylation of various substituted thioureas with bis-imidochlorides of oxalic acid the new thiazolidines 3, 4 and isomeric imidazolidines 5, 6 are obtained. Especially when triethylamine is used as a base the main products are the deeply coloured 4-arylimino-5-thioxo-imidazolidines which can be regarded as s-cis-configurated 1,4-dihetero-1,3-dienes. Some thiazolidines can be rearranged by means of anhydrous organic acids to parabanic acid derivatives; whereas the 5-thioxo-imidazolidines result from an intramolecular 1,3-acyl rearrangement during the reaction.
Lee; Jung; Kim, Polish Journal of Chemistry, 2009, vol. 83, # 10, p. 1765 - 1770