UNSYMMETRICAL INDOLODIMETHYLIDYNECYANINES AND THEIR PROPERTIES

Article abstract of DOI:10.1007/BF00568947

New unsymmetrical dimethylidynecyanines with various substituents in the heterocyclic rings were obtained by condensation of 1-methyl-2-arylindoles that contain a formyl group in the 3-position with quaternary salts of 2-methyl-substituted benzoxazoles, benzothiazoles, 3,3-dimethylindolenines, and benzoselenazoles in acetic anhydride by heating in the presence of p-toluenesulfonic acid.Unsymmetrical dimethylidynecyanines with residues of substituted thiazoles were similarly synthesized.The spectral, polarographic, and photographic characteristics of the dyes obtained were studied.It is shown that, depending on their structure, they absorb in different zones of the spectrum and can be used for the spectral sensitization of direct positive recording materials to various parts of the spectrum.