Synthesis and fluorescent properties of some heterobifunctional and rigidized 7-aminocoumarins

Heterobifunctional fluorescent reagents of coumarin type are synthesized. They possess, in position 7 , a rigidized or un-rigidized amino group and, in position 3 or 4 , a carboxylic function. The fluorescence characteristics of these compounds are described and compared with the 7-amino-4-methylcoumarin. The influence of the relative freedom of rotation of the amino group or the position of the acid function on the fluorescence properties are also studied.