Triethylamine → 5-Chloro-2-(methylthio)benzothiazole

Beteiligte Stoffe

Reaktionsschritte

3-Methyl-1-phenylpyrazolin-5-one (1.045 g) was mixed with 2.03 g (0.006 mol) 2-methylthio-5-chloro-3-(3'-sulfopropyl)benzothiazolium, inner salt in 50 ml methanol. Triethylamine (0.62 g) was added. The mixture was stirred for one hour, the solvent evaporated, and the residue dissolved in isopropanol. The resulting solution was treated with 0.6 g KOAc in methanol to precipitate the dye. Filtering yielded 2.17 g (72%), mp 271°-276° C., λmax=383 (ε=19,000).

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