Unexpected pyrazolo[4,3-d][2,3]benzodiazepine synthesis from 1-(N,N-diaroyl)amino-4-phenyl-[1,2,3]triazol-5-yl-methyltriphenylphosphonium bromide via tandem phosphorylide formation and subsequent Dimroth-like rearrangement of the triazole ring
作者:Efstathios Laskos、Pygmalion S. Lianis、Nestor A. Rodios、A. Terzis、C.P. Raptopoulou
DOI:10.1016/0040-4039(95)01034-f
日期:1995.7
giving the very stable phosphorus ylide 5. Refluxing of 5 in xylene gave the unexpected 3-aroyl-6-arylpyrazolo[4,3-d][2,3]benzodiazepines6 by a Dimroth-like rearrangement of the triazole ring and a 1,7-electrocyclization of the nitrilimine intermediate 11. When the xylene solution was not rigorously refluxed the 3(5)-aroyl-5(3)-phenyl pyrazole 7 was isolated. The x-ray crystal structures of compounds
1-(N,N-二芳酰基)氨基-4-苯基-1,2,3-三唑-5-基-甲基三苯基溴化phosph 2与叔丁醇钾或三乙胺在干燥的甲苯中反应,得到非常稳定的磷内鎓盐5。5在二甲苯中的回流通过三唑环的类似Dimroth的重排和腈腈胺中间体的1,7-电环化作用产生了意外的3-芳酰基-6-芳基吡唑并[4,3- d ] [2,3]苯并二氮杂卓6 11。当不严格回流二甲苯溶液时,分离出3(5)-芳酰基-5(3)-苯基吡唑7。还给出了化合物5d和6b的X射线晶体结构。