Synthesis of [1]benzopyrano[2,3,4-kl]acridin-3-ol and its analogues as pentacyclic compounds

A new heterocyclic compound, 1]benzopyrano2,3,4-kl]acridin-3-ol was synthesized by cyclization of xanthone derivatives. The key compound, 1-(3'-methoxyanilino)-xanthone, was prepared from 1-aminoxanthone. 1]benzopyrano2,3,4-kl]acridin-3-ol analogues, 1]benzothiopyrano2,3,4-kl]acridin-3-ol, pyrido3',2':5,6]pyrano2,3,4-kl]acridin-3-ol and pyrido3',2':5,6]thiopyrano2,3,4-kl]acridin-3-ol were synthesized by the same method.