625-52-5Relevant articles and documents
A Straightforward Synthesis of N-Substituted Ureas from Primary Amides
Franck, Xavier,Glachet, Thomas,Ibert, Quentin,Lohier, Jean-Fran?ois,Reboul, Vincent,Saraiva Rosa, Nathalie
, p. 2099 - 2105 (2020/07/13)
A direct and convenient method for the preparation of N-substituted ureas is achieved by treating primary amides with phenyliodine diacetate (PIDA) in the presence of an ammonia source (NH 3 or ammonium carbamate) in MeOH. The use of 2,2,2-trifluoroethanol (TFE) as the solvent increases the electrophilicity of the hypervalent iodine species and allows the synthesis of electron-poor carboxamides. This transformation involves a nucleophilic addition of ammonia on the isocyanate intermediate generated in situ by a Hofmann rearrangement of the starting amide.
Synthesis and Structure of 1-Substituted Semithioglycolurils
Baranov, Vladimir V.,Galochkin, Anton A.,Kravchenko, Angelina N.,Makhova, Nina N.,Nelyubina, Yulia V.
, p. 2563 - 2571 (2020/09/07)
Two methods for the synthesis of previously unavailable 1-substituted semithioglycolurils were developed. These methods consist of the cyclocondensation of 1-substituted ureas with 4,5-dihydroxy- or 4,5-dimethoxyimidazolidine-2-thione or glyoxal, followed by the reaction of the resulting 1-substituted 4,5-dihydroxyimidazolidine-2-ones with HSCN in a two-step one-pot procedure. Two of the desired semithioglycolurils were obtained as conglomerates.
Metal-Free Ring-Expansion Reaction of Six-membered Sulfonylimines with Diazomethanes: An Approach toward Seven-Membered Enesulfonamides
Xia, An-Jie,Kang, Tai-Ran,He, Long,Chen, Lian-Mei,Li, Wen-Ting,Yang, Jin-Liang,Liu, Quan-Zhong
supporting information, p. 1441 - 1444 (2016/02/12)
A new metal-free, ring-expansion reaction of six-membered N-sulfonylimines with unstable diazomethanes, generated in situ from the N-tosylhydrazones, has been developed. This reaction delivers valuable seven-membered enesulfonamides by a Tiffeneau-Demjanov rearrangement and intramolecular proton transfer tautomerization process. Moreover, this ring-expansion reaction can be carried out in a one-pot fashion and scaled up to the gram scale by using aryl aldehydes, without the need to isolate the N-tosylhydrazone. A diazo thing: The title reaction between cyclic N-sulfonylimines and diazo compounds generated in situ from the N-tosylhydrazones is simple and functional-group tolerant. It thus delivers valuable seven-membered sulfonamides in up to 95 % yield. Moreover, this reaction can be carried out in one-pot starting from the aryl aldehydes, without the need to isolate the N-tosylhydrazone (right).
