60870-71-5Relevant articles and documents
Reaction Between 2-Aminoazoles and Picryl Derivatives: Products and Structures
Forlani, Luciano,Guastadisegni, Grazia,Raffellini, Luca,Todesco, Paolo E.,Foresti, Elisabetta
, p. 493 - 499 (2007/10/02)
The reactions of some 2-pyridinamine derivatives with 2,4,6-trinitro-chlorobenzene (or -fluorobenzene) afford products of condensation on the exocyclic nitrogen. 2-Thiazolamine derivatives react with picryl halides with both nitrogen atoms, exocyclic and endocyclic and, in some cases, with the carbon in position 5 of the thiazole ring.The structures of some of the products of the reactions reported in the literature are revised and corrected (also by X-ray diffraction) for both thiazole and pyridine systems.The difference in behaviour of two aminoazoles is explained by differences in the electron-releasing power of the amino group toward the nitrogen which is more effective in withdrawing electrons in the thiazole system thanin the pyridine one.The regioselectivity of the attack of the electrophiles to 2-thiazolamine is explained by the different polarizability requirements of the three centres involved, and by their different steric reguirements.From 1H NMR spectral data, it is possible to state that N-picryl-2-thiazolamine is mainly in the imino form in polar solvents, while the amino form predominates in apolar solvents.
