Synthesis of an Ethyl 6-Amino-3,5-difluorosalicylate Derivative by Sequential Regioselective Directed ortho-Metalation, A Practical Synthesis of4,5-Diamino-3,6,8-trifluoroflavone, A Potent Antitumor Agent - Akama, Tsutomu; Ueno, Kimihisa; Saito, Hiromitsu; Kasai, Masaji (Synthesis, 1997)