Syntheses with Nitriles, LXXXIII: On Dicyanomethylene-aminoindenes, Indano-pyridazines and Indano-pyridines

Article abstract of DOI:10.1007/BF00809972

1-Dicyanomethylene-3-indanone (1) shows a remarkable reactivity of the carbonyl- and the methylene-function towards nucleophiles.With anilines and phenylhydrazine, resp., the deep-red colored pentamethinecyanines 2 and 3 are formed, azocoupling leads to indano-pyridazines 4.With diphenylformamidines anilinomethylene-indanones 5 are obtained in a primary reaction, followed by ring closure and Dimroth-rearrangement to indano-pyridines 6. 13C- and 15N-NMR-spectroscopy is used for confirmation of the structures. - Keywords: 1-Dicyanomethylene-3-indanone; 1-Dicyanomethylene-3-phenylamino-2-indenes; Indano-(2,1-c)pyridazines; Phenylamino-indano-(2,1-c)pyridines.