method for preparing 2-(N-substituted)-amino-benzimidazole derivatives
申请人:Jiang Yueheng
公开号:US20130345436A1
公开(公告)日:2013-12-26
A method for preparing 2-(N-substituted)-amino-benzimidazole derivatives is provided, which comprises the following steps: (1) reacting a compound of 2-(N-protecting group)-O-aryl diamine with a compound of N-phenoxycarbonyl monosubstituted amine to obtain a compound of 2-(N-protecting group)-amino aryl urea; (2) in a suitable organic solvent, performing dehydrating cyclization reaction of the compound of 2-(N-protecting group)-amino aryl urea in the presence of an organic base and dichloro triphenylphosphine prepared by triphenylphosphine oxide with oxalyl chloride or diphosgene or triphosgene, or dibromo triphenylphosphine prepared by triphenylphosphine oxide with bromine, to produce a compound of 1-protecting group-2-(N-substituted)-amino-benzimidazole; (3) deprotecting the resulting compound of 1-protecting group-2-(N-substituted)-amino-benzimidazole to obtain the compound 2-(N-substituted)-amino-benzimidazole.
An intramolecular Cu-catalyzed asymmetric propargylic [4 + 2] cycloaddition of bis-N-nucleophile-functionalized propargylic esters has been realized in the support of a chiral tridentate N-ligand, (S,S)-Pybox-diOAc, leading to chiral tetrahydroisoindolo[2,1-a]quinoxalines in high yields and with good to excellent enantioselectivities. The reaction features high efficiency, simplicity, and broad substrate
在手性三齿 N-配体 ( S , S )-Pybox-diOAc 的支持下,实现了双-N-亲核试剂官能化的炔丙基酯的分子内 Cu 催化的不对称炔丙基 [4 + 2] 环加成反应,从而产生手性四氢异吲哚[2,1- a ]喹喔啉的收率高,对映选择性良好。该反应具有高效、简单和广泛的底物范围,从而为立体选择性获得原本难以合成的光学活性多环杂环骨架提供了强大而简洁的策略。
DDQ in mechanochemical C–N coupling reactions
作者:Shyamal Kanti Bera、Rosalin Bhanja、Prasenjit Mal
DOI:10.3762/bjoc.18.64
日期:——
that DDQ can be used to synthesize 1,2-disubstitutedbenzimidazoles and quinazolin-4(3H)-ones via the intra- and intermolecular C–N coupling reaction under solvent-free mechanochemical (ball milling) conditions. In the presence of DDQ, the intramolecularC(sp2)–H amidation of N-(2-(arylideneamino)phenyl)-p-toluenesulfonamides leads to 1,2-disubstitutedbenzimidazoles and the one-pot coupling of 2-aminobenzamides
2,3-二氯-5,6-二氰基-1,4-苯醌(DDQ)是一种众所周知的氧化剂。在此,我们报道DDQ可用于在无溶剂机械化学(球磨)条件下通过分子内和分子间C-N偶联反应合成1,2-二取代苯并咪唑和喹唑啉-4(3 H )-酮。在 DDQ 存在下, N -(2-(亚芳基氨基)苯基)-对甲苯磺酰胺的分子内 C(sp 2 )–H 酰胺化生成 1,2-二取代苯并咪唑,以及 2-氨基苯甲酰胺与芳基/烷基醛以高产率产生取代的喹唑啉-4(3 H )-酮衍生物。
NaI-Mediated Electrochemical Cyclization–Desulfurization for the Synthesis of <i>N</i>-Substituted 2-Aminobenzimidazoles
An electrochemical method for the synthesis of N-substituted 2-aminobenzimidazoles through a NaI-mediated desulfurization–cyclization process is reported. This electrosynthesis method utilizes cost-effective NaI as both a mediator and an electrolyte in a catalytic amount (0.2 equiv), replacing traditional oxidizing reagents. N-Substituted o-phenylenediamines and isothiocyanates undergo a thiourea
报道了一种通过 NaI 介导的脱硫环化过程合成N-取代 2-氨基苯并咪唑的电化学方法。这种电合成方法利用经济高效的 NaI 作为介体和催化量(0.2 当量)的电解质,取代了传统的氧化剂。 N-取代的邻苯二胺和异硫氰酸酯经过硫脲形成/环化/脱硫过程,在单个反应容器中提供N-取代的2-氨基苯并咪唑(55个实例,产率高达98%)。重要的是,这种电化学方法适用于克级合成,保持反应效率。