HETEROCYCLES

■ Novel Twin-Drug Type C2-Symmetrical Phenylboronic Acid Pinacol Esters

Makoto Furutachi, Ayumi Ejima, Reika Tsuru, Saho Goto, Toshiaki Gondo, Kenta Ako, Saya Fujii, Arisa Okumura, Ayumi Tozuka, Kazumi Yokomizo, Jian-Rong Zhou, Hiroshi Inao, Yutaro Ono, Nobuhiro Kashige, Fumio Miake, and Kunihiro Sumoto*

*Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan

Abstract

We here report the preparation of newly designed bivalent twin-drug type C2-symmetrical cyclic phenylboronic acid derivatives. The synthesis of these C2-symmetrical mid-size molecules 3 was accomplished by an amide bond formation reaction using amino-substituted phenylboronic acid pinacol esters 1 and dicarboxylic acid dichlorides 2 in the presence of Et3N. We confirmed that this procedure is conventionally applicable to the preparation of various C2-symmetrical cyclic boronic acid derivatives 3 in good to excellent yields.