6488-97-7Relevant articles and documents
THE (1)H AND (13)C N.M.R. RULES FOR THE ASSIGNMENT OF 1,3- AND 1,5-DISUBSTITUTED PYRAZOLES: A REVISION
Bruix, Marta,Mendoza, Javier de,Elguero, Jose
, p. 4663 - 4668 (1987)
The H-5 signal of N-substituted pyrazoles is not shifted to low field values on increasing solvent polarity when a nitrogen lone pair lies very close to the measured proton (H-bond).Typical examples of this "abnormal" behaviour are provided by C,N'-linked, pyrazole-containing heterocyclic dimers.On the contrary, models selected in the 1,1'-bipyrazole and 2,2'-biindazole series (N,N'-linkage) showed normal shifts, due to their non-coplanar conformation around the N-N bond.For the assignment of disubstituted pyrazoles, a proton-coupled (13)C n.m.r. spectrum is recommended as an alternative method.
Direct, metal-free amination of heterocyclic amides/ureas with NH-heterocycles and N-substituted anilines in POCl3
Deng, Xiaohu,Roessler, Armin,Brdar, Ivana,Faessler, Roger,Wu, Jiejun,Sales, Zachary S.,Mani, Neelakandha S.
experimental part, p. 8262 - 8269 (2011/12/04)
A POCl3-mediated, direct amination reaction of heterocyclic amides/ureas with NH-heterocycles or N-substituted anilines is described. Compared to the existing methods, this operationally simple protocol provides unique reactivity and functional
