Studies on Cyanine Dyes. III

Syntheses of Merocarbo and Polymethine Cyanine Dyes from Sodium Salts of Formyl Compounds

Abstract

Merocarbocyanine dyes were prepared by reacting quinaldine methiodide or ethiodide, 2-methylbenzothiazole ethiodide, or 2-methyloxazole ethiodide, with several kinds of formyl compounds, formylcyanoacetate, formylacetate, or 2-formyl-3(2H)-thionaphthe-none, or several kinds of sodium salts of formyl compounds, formylacetone, formylacetophenone, or the sodium salt of 4-formyl-1, 3-indandione. Pentamethine cyanine dyes possessing phenyl or methyl substituents in the β-position were prepared by reacting one-half molar equivalent of the sodium salt of formylacetophenone or formylacetone to quinaldine methiodide.