Selenation of 1,5-Naphthoquinones: Novel Synthesis of Naphthopyridoselenazines

Abstract Selenation of 2-chloro- and 2,6-dichloro-1,5-naphthoquinones with benzeneselenolate ion, generated from diphenyl diselenide and tributylphosphine in an alkaline medium, afforded 2-phenylseleno- and 2,6-bis(phenylseleno)-1,5-naphthoquinones in excellent yields. Reaction of halo-1,4-naphthoquinones with 3-amino-2-pyridineselenolate ion generated from bis(3-amino-2-pyridyl) diselenide gave naphtho[2,1-b]pyrido[3,2-e][1,4]selenazines and pyrido[2,3-b]pyrido[3″,2″:5′,6′][1,4]selenazino[2′,3′:3,4]naphtho[1,2-e][1,4]selenazines in high yields.