Cyclic acyl amidines as unexpected C4-donors for fully substituted pyridine ring formation in the base mediated reaction with malononitrile

Abstract A new one-step, pseudo four-component approach for the synthesis of fully substituted pyridines via ring-opening of the cyclic acyl amidine of 3-amino-1 H -isoindol-1-one and its aza-analogues during the reaction with malononitrile in the presence of sodium methoxide, followed by pyridine ring closure is reported. This method allows the one-step preparation of previously unknown 2-(pyridin-4-yl)(hetero)aryl carboxamides in good yields under mild reaction conditions.