Bromineless Bromine as an Efficient Desulfurizing Agent for the Preparation of Cyanamides and 2-Aminothiazoles from Dithiocarbamate Salts
作者:Ramesh Yella、Veerababurao Kavala、Bhisma K. Patel
DOI:10.1080/00397911003642658
日期:2011.2.28
desulfurizing agent in the preparation of organic cyanamides and substituted thiazoles starting from dithiocarbamic acid salts. In this approach, alkyl/aryl isothiocyantes were first obtained by the desulfurization of dithiocarbamic acid salts with EDPBT. The in situ–generated isothiocyanates reacts with an aqueous ammonia, forming alkyl or aryl thioureas, which on subsequent oxidative desulfurization
摘要 在以二硫代氨基甲酸为原料制备有机氰胺和取代噻唑的过程中,无溴溴化试剂 1,1'-(乙烷-1,2-二基)二溴化吡啶鎓 (EDPBT) 已被用作脱硫剂。盐。在这种方法中,烷基/芳基异硫氰酸酯首先通过二硫代氨基甲酸盐与 EDPBT 脱硫获得。原位生成的异硫氰酸酯与氨水反应,形成烷基或芳基硫脲,随后用 EDPBT 氧化脱硫,以良好的收率形成相应的氰胺。或者,通过原位生成的 1-芳基硫脲与由酮原位生成的 α-溴酮缩合,再次使用 EDPBT,实现了取代噻唑的高效一锅法合成。试剂 EDPBT 可以很容易地从现成的试剂中制备。对于易于溴化的底物,脱硫能力优于其溴化能力。