flash vacuum thermolysis (FVT) with Ar matrix isolation of the product. Matrixphotolysis of 16 affords diazo compound 15, cyclic ketenimine 19 and open‐chain ketenimine 26. 2‐Quinoxalinylcarbene 17 was also formed in the matrixphotolysis and identified by its ESR spectrum. FVT of either 22 or 15/16 afforded 4‐quinolylnitrene, identified by its Ar‐matrix ESR spectrum. A second nitrene ESR signal obtained
通过电子自旋共振(ESR)和红外(IR)光谱鉴定,4-喹啉基叠氮化物22的基质光解可得到4-喹啉基硝烯21。还观察到分配给叠氮苯23(1741 cm -1)的次要吸收。进一步的光解作用会在1902和1909 cm -1处归因于环状酮亚胺19,而在2044 cm -1处归因于开链酮亚胺26且在1982 cm -1处具有较弱的吸收,归因于开环腈。25。2-(5-四唑基)喹喔啉14和三唑并[1,5- a对喹喔啉16在2084 cm -1处产生吸收,这是由于重氮化合物15在温和的快速真空热解(FVT)中形成,并带有Ar基质分离产物。16的基质光解得到重氮化合物15,环状酮亚胺19和开链酮亚胺26。2-喹喔啉基卡宾17也在基质光解中形成,并通过其ESR光谱进行鉴定。FVT为22或15/16时,可以得到4-喹啉基亚硝烯,由Ar-矩阵ESR光谱确定。在两个FVT和光解实验中从这22个中获得的第二个氮烯E
SNAr azidation of phenolic functions utilizing diphenyl phosphorazidate
A useful method for the synthesis of aryl azides via SNAr reaction of phenol derivatives using diphenyl phosphorazidate (DPPA) as an azidationreagent was developed. Various phenol derivatives bearing electron-withdrawing groups were converted into the corresponding aryl azides in a single step. This method is easy to perform and enables the preparation of aryl azides without the use of explosive azide
A series of novel triazole nucleobase analogues containing steroidal/coumarin/quinoline moieties have been synthesized based on copper-catalyzed azide-alkyne cycloaddition (CuAAC). The anti-cancer activity of the new triazole nucleobase analogues was studied in gastric cancer cell lines (MGC-803, SGC-7901) and normal gastric epithelial cells (GES-1) in vitro. Some of the synthesized compounds could
neurotoxicity of Aβ fibrils. It is known that AChE has two binding sites: the peripheralsite, responsible for the interactions with Aβ, and the catalytic site, related with acetylcholine hydrolysis. In this work, we reported the synthesis and biological evaluation of a library of new tacrine-donepezil hybrids, as a potential dual binding site AChE inhibitor, containing a triazole-quinoline system. The synthesis