Reactions of 1,4-naphthoquinone with aza-ortho-xylylenes generated via ther
mal extrusion of SO2 from 2,1-benzisothiazoline 2,2-dioxides (benzosultams)
lead to tetrahydronaphthalene 2-spiro-2'-dihydroindole derivatives. Aza-or
tho-xylylene generated via thermal ring opening of 1-phenylbenzazetidine ga
ve with naphtboquinone benzo[b]acridine derivative 15.