Synthesis of fluorinated indazoles through ANRORC-like rearrangement of 1,2,4-oxadiazoles with hydrazine
作者:Antonio Palumbo Piccionello、Andrea Pace、Ivana Pibiri、Silvestre Buscemi、Nicolò Vivona
DOI:10.1016/j.tet.2006.06.100
日期:2006.9
A series of 6-substituted fluorinated indazoles has been obtained through an ANRORC-like rearrangement (Addition of Nucleophile, Ring-Opening and Ring-Closure) of 5-tetrafluorophenyl-1,2,4-oxadiazoles with hydrazine. The initial addition of the bidentate nucleophile to the electrophilic C(5) of the 1,2,4-oxadiazole ring, followed by ring opening and ring closure, leads to the formation of fluorinated
通过5-四氟苯基-1,2,4-恶二唑与肼的类似ANRORC的重排(亲核试剂的加成,开环和闭环)获得了一系列6-取代的氟化吲唑。最初将双齿亲核试剂添加到1,2,4-恶二唑环的亲电C(5)中,然后开环和闭环,导致在温和的实验条件下以高收率形成氟化吲唑。最终吲唑核中的C(6)功能化是通过在起始5-五氟苯基-1,2,4-恶二唑上进行亲核芳香取代而初步实现的。