Synthesis of novel monomeric and homodimeric cyanine dyes with thioacetyl substituents for nucleic acid detection

Several novel di-, tri- and tetracationic monomeric and homodimeric monomethine cyanine dyes for nucleic acid detection were synthesized by condensation of 3,4-dihydro-(2H)-1,3-thiazino[2,3-b]benzooxazolium bromide and appropriate 1-(ω-bromoalkyl)-4-methylpyridinium or 1-(ω-bromoalkyl)-4-methylquinolinium bromide followed by quaternization with N,N,N′,N′-tetramethyl-1,3-propanediamine (TMPDA) or N,N,N,N′,N′-pentamethyl-1,3-propanediammonium iodide, or bisquaternization with TMPDA or N,N,N′,N′-tetramethyl-1,6-hexanediamine (TMHDA).