J. Mirek, P. Milart
Nov 1, 1986
Citations
0
Influential Citations
8
Citations
Journal
Zeitschrift für Naturforschung B
Abstract
Abstract It was found that instead of the Knoevenagel condensation of cyclopentylidenemalononitrile with aromatic aldehydes, a complex reaction takes place leading to 5,7-dicyano-1-arylidene-4-arylindanes. The same compounds were formed in the reaction of the cyclopentylidenemalononitrile dimer with aldehydes. It is suggested that the cyclopentylidenem alononitrile dimers undergo an electrocyclic ring opening leading to conjugated triene systems. These species are very reactive intermediates and may react with aldehydes in the next step. Bulky substituents in 2,5-dibenzylidenecyclopentanone hindered its Knoevenagel condensation with malononitrile but did not hinder its Michael addition leading to a 4H -pyrane derivative. Solutions of the obtained o-aminonitriles exhibit strong fluorescence in a variety of solvents.