Polymethine dyes derived from boron complexes of, acetylhydroxycoumarins

Novel dyes were obtained by condensation of boron derivatives of 3-acetyl-4-hydroxy- or 7-hydroxy-8-acylcoumarin with triethyl orthoformate of Fischer's aldehyde. The reaction of the former boron complexes with DMF followed by condensation of the resultant hemicyanine with dimethylquinolinium iodides furnished non-symmetric polymethine dyes with a quinoline its the terminal heterocyclic unit. (C) 2003 Elsevier Science Ltd. All rights reserved.