SYNTHESIS AND PROPERTIES OF SUBSTITUTED INDOLO-3-CYANINE DYES

Article abstract of DOI:10.1007/BF00503660

Indolo-3.3'-mono- and indolo-3,3'-trimethylidynecyanines that contain substituents in the indole rings and in the polymethine chain (in the case of trimethylidynecyanines) were synthesized by condensation of 2-alkyl- and 2-arylindoles, respectively, with ethyl orthoformate and tetraalkylacetals of substituted malonic dialdehydes in anhydrous benzene in the presence of acetyl chloride or thionyl chloride.The colors of the products were studied, and the polarographic potentials of the oxidation and reduction half waves were determined.A relationship between the indicated characteristics of indolo-3-cyanines and their structure was established.