Replacement of the Hetarene Moiety of Molecule in the Synthesis of Indoline Spiropyran with Cationic Fragment

The paper describes the preparation of a new salt spiropyran of indoline series containing vinyl-3H-indolium fragment in the 8' position of the 2H-chromene moiety and a chlorine atom in the benzene ring of the indoline fragment. The structure of the reaction product was studied by IR, 1H, and 13C NMR spectroscopy. The data of X-ray diffraction study indicate that the reaction leads to the partial exchange of the indoline hetarene fragment to provide previously described salt spiropyran containing no chlorine atom in the indoline portion of the molecule.