Abstract
3′-O-Aralkyl-5-(4-biphenylcarboxamido)- and 3′-O-aralkyl-5-{N′-(3,5-dimethylphenyl)thioureido} fluorescein derivatives are prepared in high yield by alkylation of 5-(4-biphenylcarboxamido)-and 5-{N′-(3,5-dimethylphenyl)thioureido]fluoresceins.