Catalytic Oxidation of N-Phenylamidrazones to 1,3-Diphenyl-1,4-dihydro-1,2,4-benzotriazin-4-yls: An Improved Synthesis of Blatter’s Radical
作者:Panayiotis Koutentis、Daniele Lo Re
DOI:10.1055/s-0029-1218782
日期:2010.6
Blatter’s radical, 1,3-diphenyl-1,4-dihydro-1,2,4-benzotriazin-4-yl (1a, R = H), and several of its C-7 substituted analogues (R = CF3, Cl, Br, I, Me, OMe) were prepared in good-to-excellent yields through catalytic oxidation of the corresponding amidrazones by using palladium-on-carbon (1.6 mol%) and 1,8-diazabicyclo[5.4.0]undec-7-ene (0.1-1.0 equiv) in air. The reaction conditions were suitable for the preparation of Blatter’s radical on a one-gram scale in up to 87% yield.
通过使用碳上钯(1.6 mol%)和 1,8-二氮杂双环[5.4.0]十一碳-7-烯(0.1-1.0 等效当量)在空气中催化氧化相应的脒酮,制备了 Blatter 的自由基 1,3-二苯基-1,4-二氢-1,2,4-苯并三嗪-4-基(1a,R = H)及其多个 C-7 取代的类似物(R = CF3、Cl、Br、I、Me、OMe),并获得了良好到极佳的收率。6 mol%)和 1,8-二氮杂双环[5.4.0]十一-7-烯(0.1-1.0 等量级)在空气中催化氧化制备了相应的脒酮类化合物,收率良好。该反应条件适用于制备一克级的 Blatter 自由基,收率高达 87%。