A synthetic route for substituted telluracarbocyanine dyes (8a～b) is described. Treatment of 4-chloroaniline (1) with equimolar amounts of mercury acetate, lithium chloride and excess acetic anhydride gave 2 in high yield. The aryl mercury chloride (2) refluxed with an equimolar amount of tellurium tetrachloride in acetic acid gave compound 3 (inner salt). Reduction of 3 with hydrazine hydrate produced 4, which could be further reduced with sodium borohydride and then alkylated with methyl iodide to give compound 5 Compound 6 could be synthesized from 3,4, or 5 under different conditions, respectively. Alkylation of 6 with methyl or ethyl ioide formed quaternary ammonium salts (7a～b) which could be condensed with ethyl orthoformate in acetic anhydride to give symmetric telluracarbocyanine dyes (8a～b), The visible absorption of the dyes is also discussed.

Key words: SPECTRAL SENSITIZATION, CYANINE DYES