Synthesen mit Nitrilen, LXXXVII. Chromoionophore durch Addition von <i>N</i>‐Phenyl(aza‐15‐krone‐5) an reaktive Dicyanmethylenverbindungen

Abstract

Syntheses with Nitriles, LXXXVII. — Chromoinophores by Addition of N ‐Phenyl(aza‐15‐crown‐5) to Reactive Dicyanomethylene Compounds Addition of N ‐phenyl(aza‐15‐crown‐5) ( 2 ) to dicyanomethylene compounds, i.e. the pyrazolylidenemalonitriles 1a – e , leads to the colorless (azacrownphenyl)(pyrazolyl)malonitriles 3a – e . Heating or photolysis of 3 eliminates hydrocyanic acid to give the deeply colored polymethines 4a – e . A corresponding reaction occurs between the indanylidenemalonitrile 5 and the crown ether 2 leading to adduct 6 , which can be converted into the polymethine 7 by heating or photolysis. For evaluation of constants of the complex formation with sodium or potassium ions 1 H NMR chemical shift measurements have been performed.