3,6-Disubtituted fluorans containing 4(3H)-quinazolinon-3-yl, diethyl amino groups and their application in reversible thermochromic materials

3,6-Disubstituted fluorans containing 4(3H)-quinazolinone-3-yl and diethylamino groups were synthesized by reacting 4-diethylamino-2-hydroxy-2′-carboxybenzophenone with various 4(3H)-quinazolinones in the presence of dehydration condensing agent. These 4(3H)-quinazolinones were derived by reacting various substituted benzoxazine-4-ones with 3-aminophenol. All the fluorans have been identified by conventional methods (IR, 1H NMR), elemental analysis, and UV–visible spectroscopy in organic solvent and 95% acetic acid. These fluorans have been applied in reversible thermochromic materials.