Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Preparation and thermal behaviour of 1-substituted 2-dicyanomethylene-1,2-dihydropyridines : Synthesis of 2-pyridyl malononitriles. ... 1-Substituted 2-methylthio-4,6-diphenylpyridinium iodides ( ) react with malononitrile under the influence of bases to give 1-substituted 1,2- ...