PROCESS FOR PREPARATION OF CYANINE DYE HAVING POLYSULFONATE ANION

摘要

PROBLEM TO BE SOLVED: To provide a convenient and economical method for preparing an infrared absorbing cyanine dye useful for a lithographic printing plate precursor. SOLUTION: A reaction for the preparation is generally carried out by condensation of a heterocyclic base containing an activated methylene group and an unsaturated bisaldehyde or its equivalent substance in a solvent or solvent mixture at about 20-150°C. All the reactions necessary for production of the infrared absorbing cyanine dye may be carried out in one reaction vessel without isolating any intermediate product. COPYRIGHT: (C)2005,JPO&NCIPI