An efficient and mild oxidative desulfurization procedure using o-iodoxybenzoic acid has been developed for the synthesis of carbodiimides starting from easily synthesizable 1,3-disubstituted thioureas.
Highly efficient and catalyst-free synthesis of unsymmetrical thioureas under solvent-free conditions
作者:Azim Ziyaei Halimehjani、Yaghoub Pourshojaei、Mohammad R. Saidi
DOI:10.1016/j.tetlet.2008.10.063
日期:2009.1
A highlyefficient and simple synthesis of unsymmetrical thioureas is reported based on the reaction of readily synthesized dithiocarbamates with amines, without using any catalyst under solvent-free conditions. The short reaction time, high yields, and solvent-free conditions are advantages of this method. We did not observe the formation of any symmetric disubstituted thiourea, under these reaction
Novel Synthesis of 2,4-Dihydro-5-amino[1,2,4]triazol-3-ones from 1,3-Disubstituted Thioureas
作者:Weike Su、Can Jin、Chuangwei Liu
DOI:10.1055/s-0028-1087563
日期:2009.3
A facile two-step synthesis of 2,4-dihydro-5-amino-[1,2,4]triazol-3-ones is described. Firstly, 1,3-disubstituted thioureas reacted with bis(trichloromethyl) carbonate (BTC) in the presence of a base such as NaHCO3 to form the intermediate 4-(arylimino)-1,3-thiazetidin-2-ones almost quantitatively. Then the intermediates were treated with hydrazine monohydrate to give 2,4-dihydro-5-amino[1,2,4]triazol-3-ones in high yields. In the case of highly sterically hindered thioureas, carbodiimides were unexpectedly obtained in high yields under the same conditions.
Michaelis; Linow, Chemische Berichte, 1893, vol. 26, p. 2168
作者:Michaelis、Linow
DOI:——
日期:——
Two-component initiator system (amine-free) with very good storage stability and particular suitability for acid systems
申请人:Utterodt Andreas
公开号:US20070040151A1
公开(公告)日:2007-02-22
A two-component initiator system having accelerators for curing polymerizable materials comprising the following components: (a) a hydroperoxide compound containing one or more hydroperoxide groups that are bound to a tertiary carbon; (b) a thiourea derivative; and (c) as accelerator, a copper compound which is soluble in the preparation is preferably free of amine and is particularly suited for polymerizable dental compositions.