Abstract The syntheses of selenenate/seleninate esters and related derivatives by aromatic nucleophilic substitution (SN Ar) reactions of 2-bromo-3-nitrobenzylalcohol (13) and 2- bromo-3-nitrobenzaldehyde (17) with Na 2 Se 2/nBuSeNa are described. The reaction of 13 with Na 2 Se 2 at room temperature afforded 7-nitro-1, 2-benzisoselenole (3 H)(15) instead of the desired diaryl diselenide 14. Oxidation of selenenate ester 15 with hydrogen ...