Synthesis of novel monomeric cyanine dyes containing 2-hydroxypropyl and 3-chloro-2-hydroxypropyl substituents – Noncovalent labels for nucleic acids

Several novel mono-, di- and tricationic monomethine cyanine dyes belonging to the Thiazole Orange family have been prepared via an improved synthetic procedure. The dyes, useful for nucleic acid detection, bear 2-hydroxypropyl and 3-chloro-2-hydroxypropyl substituents. All derivatives absorb in the region 476–519 nm and have a molar absorptivity of 49 000–106 000 L mol−1 cm−1. The reaction products were characterized by 1H NMR spectroscopy and elemental analysis.