R. M. El-Aal
Jun 1, 2004
Citations
0
Influential Citations
9
Citations
Journal
Dyes and Pigments
Abstract
Abstract 2-Cyanomethylene (2-ethoxy carbonylmethylene)-4,5-dihydrothiazolin-4-one 1a,b and 2-cyanomethylene (2-ethoxy carbonylmethylene)-4,5-dihydrothiazolo [3,2-a]oxazole 3a , b were synthesized as starting material. Reaction of both compounds 2a , b and 3a , b with N-methylheterocyclic quaternary salts afforded meso-substituted monomethine cyanine dyes 4a – d and 9a – d , respectively. Reaction of compounds 1a , b and 8a , b with ethyl orthoformate gave the intermediate compounds 5a , b and 10a , b , followed by the reaction with 1,2-dimethyl quinolinium iodide resulted in meso-substituted trimethine cyanine dyes 6a , b and 11a , b , respectively. Also, reaction of both 2a , b and 3a , b with 2-chlorocyclohexane-1,3-dicarboxaldehyde followed by the reaction with 1,2-dimethyl quinolinium iodide afforded the asymmetrical heptamethine dyes 8a , b and 13a , b . The new compounds were characterized by elemental analysis, visible absorption, 1 H NMR, IR Spectroscopy and Ms spectral data. Relation between the constitution and the UV/Vis spectroscopic properties of these dyes has been studied.