Regiochemical control in Diels–Alder routes to aza-anthraquinone derivatives

Abstract

Quinoline- and isoquinoline-5,8-diones react with 1-methoxycyclohexa-1,3-diene at 80 °C, the former giving 8-methoxy-1-aza-anthraquinone regiospecifically and the latter 5-methoxy-2-aza-anthraquinone regioselectively; in similar cycloadditions, substituted naphtho- and azanaphtho-quinones react with 1-dimethylamino-3-methyl-1-azabuta-1,3-diene at room temperature forming substituted mono- and di-aza-anthraquinones in high yields with high selectivity.