熔融的吡唑环系统是许多药学上重要的化合物的常见结构基序。然而,芳族2 H-呋喃[2,3- c ]吡唑环系统的衍生物的获得仍然很有限,并且它们的化学和功能性质仍未得到充分开发。当前的研究调查了使用金属催化反应从易于获得的起始原料构建该系统的途径。通过使用银(I)离子介导的4-炔基-3-羟基-1-苯基的闭环反应,开发了一种简单有效的访问2 H-呋喃并[2,3- c ]吡唑环系统的方法-1高-吡唑类是关键步骤。该反应所需的中间体羟基炔基底物通过4-碘-1-苯基-1H-吡唑-3-醇与乙炔衍生物的钯催化偶联制备。通过详细的1 H,13 C和15 N NMR光谱实验,HRMS和单晶X射线衍射分析明确确认了所获得目标化合物的结构。这种由银(I)介导的易于获得的4-炔基-3-羟基-1 H-吡唑类化合物的5-内切环化可以用作获得许多新颖的2,5-二取代的2 H-呋喃的有效方法[2]。 ,3- c ]吡唑。
A novel, straightforward, and highly regioselective 4-chlorination of 3-oxypyrazole derivatives in boiling thionyl chloride (SOCl2) in the presence of catalytic N,N-dimethylformamide (DMF) has been developed. This reaction likely proceeds through a DMF-catalyzed electrophilic/nucleophilic chlorination mechanism and involves electrophilic attack by SOCl2 and nucleophilic substitution by Cl– as the key
Pd-catalyzed cross-coupling reactions of halogenated 1-phenylpyrazol-3-ols and related triflates
作者:Eglė Arbačiauskienė、Gytė Vilkauskaitė、Gernot A. Eller、Wolfgang Holzer、Algirdas Šačkus
DOI:10.1016/j.tet.2009.07.017
日期:2009.9
1-Phenyl-1H-pyrazol-3-ol was used as a versatilesynthon for the preparation of various 1-phenyl-1H-pyrazole derivatives substituted at C-3 and C-4 of the pyrazole nucleus and at the phenyl ring para-position. Treatment of 1-phenyl-1H-pyrazol-3-ol with triflic anhydride in the presence of base gave 3-trifloyloxy pyrazole, while bromination and iodination yielded the corresponding halogenated derivatives
pharmaceutically important compounds. Nevertheless, access to derivatives of the aromatic 2H-furo[2,3-c]pyrazole ring system is still quite limited, and their chemistry and functional properties remain largely underexplored. The current study investigates routes to construct this system from easily accessible starting materials using metal-catalyzed reactions. A simple and efficient procedure to access the 2H-furo[2
熔融的吡唑环系统是许多药学上重要的化合物的常见结构基序。然而,芳族2 H-呋喃[2,3- c ]吡唑环系统的衍生物的获得仍然很有限,并且它们的化学和功能性质仍未得到充分开发。当前的研究调查了使用金属催化反应从易于获得的起始原料构建该系统的途径。通过使用银(I)离子介导的4-炔基-3-羟基-1-苯基的闭环反应,开发了一种简单有效的访问2 H-呋喃并[2,3- c ]吡唑环系统的方法-1高-吡唑类是关键步骤。该反应所需的中间体羟基炔基底物通过4-碘-1-苯基-1H-吡唑-3-醇与乙炔衍生物的钯催化偶联制备。通过详细的1 H,13 C和15 N NMR光谱实验,HRMS和单晶X射线衍射分析明确确认了所获得目标化合物的结构。这种由银(I)介导的易于获得的4-炔基-3-羟基-1 H-吡唑类化合物的5-内切环化可以用作获得许多新颖的2,5-二取代的2 H-呋喃的有效方法[2]。 ,3- c ]吡唑。