2-Methyl-4,9-dioxo-4,9-dihydrothiazolo

Acetylation of 6-amino-7-chloro-5,8-quinolinedione and subsequent replacement of the chlorine atom to a -SH and then a -SMe group gave the final linear 2-methyl-4,9-dioxo-4,9-dihydrothiazolo[4,5-g]quinoline 40 (59LA108). 

The 2-methyl-4,9-dioxo-4,9-dihydrothiazolo[4,5-.g]quinoline was first quar-temized with methyl iodide on pyridine nitrogen and then treated with IV-methyl-quinolinium-4-yl salt, affording monomethine cyanine dyes 41 to study solva-tochromism, acid-base properties, and antimicrobial activities (95MI1). 

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