Synthesis and characterization of novel substituted spiro[isobenzofuran-1(3H), 9’-xanthene]-3-ones

Abstract

The ketoacid, 2-(4-diethylamino-2-hydroxybenzoyl)benzoic acid, prepared from N,N-diethyl-m-aminophenol and phthalic anhydride, was reacted with various substituted 3-[6-methoxybenzothiazol-2-yl]-4(3H)-quinazolinones in the presence of a dehydration condensing agent to afford novel spiro[isobenzofuran-1(3H),9’-xanthene]-3-ones. The benzothiazolyl quinazolinones were synthesized by reacting 2-amino-6-methoxybenzothiazole with various substituted benzoxazinones. All compounds were characterized by melting point determination, elemental analysis, infra- red spectroscopy NMR-spectroscopy and UV-visible sprectroscopy. All the fluoran compounds are colourless or nearly colourless and produce colour in the presence of acidic media.

Keywords

• synthesis
• ketoacid
• fluoran
• benzothiazolyl quinazolinone