Department of Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut 06877, USA.
Org Lett. 2009 Dec 3;11(23):5490-3. doi: 10.1021/ol902334x.
Reaction of 4-bromo-NH-1,2,3-triazoles 2 with alkyl halides in the presence of K(2)CO(3) in DMF produced the corresponding 2-substituted 4-bromo-1,2,3-triazoles 5 in a regioselective process. Subsequent Suzuki cross-coupling reaction of these bromides provided an efficient synthesis of 2,4,5-trisubstituted triazoles 3. In addition, reduction of the bromotriazoles by hydrogenation furnished an efficient synthesis of 2,4-disubstituted triazoles 8.
4-溴-NH-1,2,3-三唑 2 与卤代烷在 K(2)CO(3)存在下于 DMF 中反应,以区域选择性方式生成相应的 2-取代 4-溴-1,2,3-三唑 5。这些溴化物的后续 Suzuki 交叉偶联反应提供了 2,4,5-三取代三唑 3 的有效合成。此外,通过氢化还原溴代三唑可有效地合成 2,4-二取代三唑 8。