Studies on Heteropentalenes. IV. Heteroannelations to Pyrrolo-[2,1-<i>b</i>]benzothiazole and Pyrrolo[2,1-<i>b</i>]thiazoles
作者:Noritaka Abe、Tarozaemon Nishiwaki、Toshimasa Omori、Emiko Harada
DOI:10.1246/bcsj.55.200
日期:1982.1
2,3-Dibenzoylpyrrolo[2,1-b]benzothiazole (2) and 6,7-dibenzoylpyrrolo[2,1-b]thiazoles (5a–b) have been synthesized by utilizing the cycloaddition reactions of imidazo[2,1-b]benzothiazole and imidazo[2,1-b]thiazoles, respectively, with dibenzoylacetylene followed by the elimination of a nitrile from each of the cycloadducts. Heteroannelations to 2 and 5 have been achieved by their reactions with hydrazine
2,3-二苯甲酰基吡咯并[2,1-b]苯并噻唑(2)和6,7-二苯甲酰基吡咯并[2,1-b]噻唑(5a-b)利用咪唑[2,1-b]的环加成反应合成b]苯并噻唑和咪唑并[2,1-b]噻唑,分别与二苯甲酰乙炔,然后从每个环加合物中消除腈。通过与肼、氨基乙腈、甘氨酸乙酯和五硫化二磷反应,已实现对 2 和 5 的杂退火。第二和第三试剂的退火相当区域选择性地进行。噻吩并[3',4':3,4]吡咯并[2,1-b]苯并噻唑和噻吩并[3',4':3,4]吡咯并[2,1-b]噻唑的简便二聚化还描述了与最后一种试剂的反应。