Synthesis of furo [3,2-g] coumarin derivatives, likely to posses antimicrobial activity

ABSTRACT

The reaction of fuming nitric acid with bergapten [I] and xanthotoxin [II] afforded the corresponding nitro derivatives [IV and V, respectively]. With imperatorin [III] the reacted with imperatorin [III] to give the phenolic compound a nitrogen-free compound [VII] resulted. Molecular bromine reacted with bergapten [VIIIa-c] in a mixture, and with xanthotoxin [II] to produce the 5-bromo derivative [IX]. Anomalously, molecular bromine reacted with imperatorin [III] to give the phenolic compound 5-bromo-9-hydroxy-furo [3,2-g] coumarin [X]. Structures of all of the final products [VIX] were confirmed by IR, H NMR and mass spectral data