Synthesis of 9-Ethyl-3,3'-Bis(3-sulfopropyl)-4,5,4'5'-Naphthothiaz Carbocyanine Triethyl Ammonium Salt
Naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization. Sensitizing dye was prepared by the reaction of 2-methyl-3- sulfopropyl-4,5-naphthothiazolium (inner salt) with triethyl orthopropionate in the presence of triethylamine. The product was identified by using various analytical tools such as elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, 1H-NMR spectrometer, TGA and DSC. The maximum absorption peak in methanol solvent was 578nm. Therefore, it was concluded that naphthothiazolo carbocyanine dye can be used as sensitizing dye for the spectral sensitization of photographic emulsion and color cosmetics.