SYNTHESIS OF FUNCTIONALIZED FLUORESCENT DYES AND THEIR COUPLING TO AMINES AND AMINO-ACIDS

A series of novel functionalised benzophenoxazinones, analogues of Nil e Red, is prepared and their fluorescence properties evaluated. The ri ng system is prepared by reaction of 5-diethylamino-2-nitrosophenol wi th 1,6-dihydroxynaphthalene followed by alkylation of the 2-hydroxy gr oup with 6-bromohexanoic acid derivatives. Subsequent ester cleavage u nder a variety of conditions gives the acid 6. Replacement of the 9-di ethylamino group with the N-ethyl-(3-sulfonylpropyl)amino group is car ried out to increase water solubility and the resulting dye 14 has sim ilar fluorescence properties. The acid 6 is coupled to a range of amin o compounds.