Synthesis and Deamination of 7,12-Dihydrobenzanthracen-7,12-imines. A New Benzanthracene Synthesis

Article abstract of DOI:10.1021/jo00210a011

The Diels-Alder reaction between isoindoles (7) and 1-naphthalyne, as generated from 1-bromo-2-fluoronaphthalene (11a), 1-bromo-2-iodonaphthalene (11b), or 1-bromo-2-naphthyl p-toluenesulfonate (11c), affords the corresponding 7,12-dihydrobenzanthracen-7,12-imine (17).Oxidative deamination of 17 with m-chloroperbenzoic acid gives the polyhalogenated benzanthracenes(3, 19a-d) in fair to good overall yields.A similar sequence with 7 and 5,6,7,8-tetrafluoro-1-naphthalyne, as generated from 1,2,3,4-tetrafluoro-5-chloronaphthalene (14a), 1,2,3,4-tetrafluoro-5-bromonaphthalene (14b), or 6-bromo-1,2,3,4-tetrafluoro- 5-naphthyl p-toluenesulfonate (16), gives, after deamination of the intermediate benzanthracenimine 18, benzanthracenes 5 and 19e in low overall yield.