The reaction of salicylic aldehydes with malononitrile was reinvestigated, and the reaction pathway was followed by 1H NMR spectroscopy. A delicate control of the experimental conditions allowed the synthesis of 2-imino-2 H-chromene-3-carbonitriles 1,(2-amino-3- cyano-4 H-chromen-4-yl) malononitriles 2, 4-amino-5-imino-2, 7-dimethoxy-5 H-chromeno [3, 4-c] pyridine-1-carbonitrile 12, and (4, 5-diamino-1-cyano-1, 10b-dihydro-2 H- ...
