Synthesis of 3,4-dihydroxy-1,8-naphthalimides with inbuilt catechol and crown ether functionalities.

Herein the synthesis of 1,8-naphthalimides functionalised as the 3,4-dihydroxy-1,8-naphthalimide (catechol, Nap-Cat) and the corresponding 15-crown-5 (Nap-Crown) is reported. These compounds represent the first examples where these two recognition groups are directly incorporated into the 1,8-naphthalimide ring system. Both Nap-Cat and Nap-Crown were evaluated for their capacity to respond to analytes such as HO (a mimic for cellular oxidation) and metal ions (as elements of environmental and physiological interest). While slow oxidation was observed for Nap-Cat upon prolonged exposure to HO, no significant changes in photophysical properties were observed upon treatment of Nap-Crown with metal ions.