Efficient Selenation of Quinones: Synthesis of Novel Benzo[b]naphtho[2,3-e]selenintrione and Dibenzo[b,e]seleninone

Selenation of 2-bromonaphthoquinone with an areneselenolate ion generated from bis(2-methoxy-carbonylphenyl) diselenide, chlorodiphenylphosphine, and LiOH afforded 2-[(2-methoxycarbonylphenyl)seleno]-1,4-naphthoquinone from which 12H-benzo[b]naphtho[2,3-e]selenin-6,11,12-trione was synthesized. 1,4-Dimethoxy-2,3-dimethyl-10H-dibenzo[b,e]selenin-10-one was prepared starting from 6-bromo-2,3-dimethylbenzoquione through the selenation and cyclization steps.