Zur Synthese von 3-Amino-pyrrolen durch Thorpe-Ziegler-Cyclisierung
作者:K. Gewald、H. Sch�fer、P. Bellmann、U. Hain
DOI:10.1002/prac.19923340608
日期:——
N-Aryl and alkylaminomethylene cyanacetic acid derivatives 1 react with alpha-halogencarbonyl compounds 2 in the presence of potassium carbonate/sodium ethoxide to yield the substituted 3-amino-pyrroles 6. Using the same principle of cyclization pyrrole derivatives 6 can also be obtained by reaction of beta-chloro- and beta-alkoxymethylenemalononitriles 4 with beta-aminocarbonyl compounds 5. From the malononitrile derivatives 1 containing the methylthio group in the beta-position, and alpha-halogen ketones 7, the 2-dicyanomethylene oxazolines 8 arise which undergo alkoholysis by treatment with sodium alkoxide to form the 3-amino-5-alkoxy-pyrrole derivatives 9.
Heterocyclic Synthesis with Activated Nitriles: An Expeditious Synthetic Approach to Polyfunctionally Substituted Pyrroles, Heterocyclopyrimidines and Coumarins
作者:Ayman W. Erian、Sherif M. Sherif、Nadia R. Mohamed
DOI:10.1081/scc-120018775
日期:2003.1.5
Abstract The applicability and synthetic potency of the new reagent N-(2,2-dicyanoethenyl)aminoacetonitrile (3) to develop an expeditious convenient synthetic route of unique polyfunctionally substituted pyrroles, heterocyclopyrimidines, and 2H-1-benzopyran-2-ones is reported. Chemical and spectroscopic evidence for the structures of the newly synthesized compounds are described.