Novel Alternative for the N<i>−</i>N Bond Formation through a PIFA-Mediated Oxidative Cyclization and Its Application to the Synthesis of Indazol-3-ones
The synthesis of a series of N,N‘-disubstituted indazolone derivatives starting from methyl anthranilates is presented. This general approach features a novel and easy way for access to the target N-heterocycles by formation of a new N−N single bond. The key cyclization step embraces the formation of an N-acylnitrenium intermediate, mediated by the hypervalent iodine reagent PIFA, and its succeeding
A concise synthesis of a benzimidazole analogue of mycophenolic acid using a BF3-Et2O catalyzed amino-claisen rearrangement.
作者:Gaifa Lai、Wayne K. Anderson
DOI:10.1016/s0040-4039(00)91811-2
日期:1993.10
A nine-step synthesis of the benzimidazole analogue, 2, of mycophenolicacid is reported involving both the BF3-Et2O catalysed aromatic amino- and the ortho ester Claisen rearrangements as key steps.
Boron trifluoride-diethyl ether complex (BF3⋅OEt2) was demonstrated to be an efficient catalyst for the amino-Claisen rearrangements of various aromatic N-allylamines into the corresponding o-allylamines in moderate yields.
2,1-Benzothiazine 2,2-Dioxides. 1. Synthesis, Structure, and Analgesic Activity of 1-R-4-Hydroxy-2,2-Dioxo-1H-2λ6,1-Benzothiazine-3-Carboxylic Acid Esters
作者:I. V. Ukrainets、L. A. Petrushova、S. P. Dzyubenko
DOI:10.1007/s10593-013-1388-9
日期:2013.12
A preparative method for the synthesis of a series of 1-R-4-hydroxy-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylates has been developed. The special features of the steric structure for compounds of this class have been studied on the example of the 1-N-methyl derivative. Results of studying the analgesic properties of the substances obtained are given.
The dehydrative allylation from allyl alcohol with amines to generate various allyl amines by MoO3/TiO2 solid catalyst is described. The catalyst can be reused at least three times without a decrease of activity.