Exploring the limitations of the MacDonald ‘3 + 1’ condensation in the preparation of porphyrins with fused electron-withdrawing heterocyclic rings: Synthesis of a bis(thiadiazolo)benzoporphyrin and a related benzocarbaporphyrin
作者:Catherine M. Cillo、Mark A. Geiger、Timothy D. Lash
DOI:10.1016/j.tetlet.2020.152576
日期:2020.11
A pyrrole ethyl ester with a fused bis(thiadiazolo)benzo unit was prepared by reacting 4-nitrobenzo[1,2-c:3,4-c’]bis(1,2,5)thiadiazole with ethyl isocyanoacetate in the presence of a non-nucleophilic base. Cleavage of the ester moiety, followed by reaction with a chloromethylpyrrole in refluxing pyridine, afforded a tripyrrane and subsequent acid-catalyzed condensation with pyrrole or indene dialdehydes
通过使4-硝基苯并[1,2- c:3,4- c' ]双(1,2,5)噻二唑与异氰基乙酸乙酯反应制得具有稠合双(噻二唑)苯并单元的吡咯乙酯。非亲核碱基。裂解酯部分,然后与氯甲基吡咯在回流的吡啶中反应,得到三吡喃,随后与吡咯或茚二醛的酸催化缩合得到结合了稠合的电子缺陷的杂环单元的卟啉类化合物。