Synthesis of Pyrrolo[2,3-d][1,2,3]thiadiazole-6-carboxylates via the Hurd-Mori Reaction. Investigating the Effect of the N-Protecting Group on the Cyclization
作者:P, Stanetty、M. Turner、M. Mihovilovic
DOI:10.3390/10020367
日期:——
A route to methyl pyrrolo[2,3-d][1,2,3]thiadiazole-6-carboxylates as potential plant activators and inducers of systemic acquired resistance (SAR) is reported. A synthetic strategy based on cyclization of the thiadiazole ring system utilizing thionyl chloride via the Hurd-Mori protocol as key step was developed. Success of the ring closure reaction turned out to be highly dependent on the nature of the N-protecting group of the pyrrolidine precursor. While electron donors such as alkyl gave only poor conversion to the required 1,2,3-thiadiazoles, an electron withdrawing substituent such as methyl carbamate gave superior yields.
报道了一条合成甲基吡咯并[2,3-d][1,2,3]硫代噻唑-6-羧酸酯的路线,该化合物具有作为潜在植物活化剂和诱导系统获得性抗性(SAR)的能力。开发了一种基于利用氯化亚硫酰通过Hurd-Mori方法环化硫代噻唑环系统的合成策略,作为关键步骤。环化反应的成功高度依赖于吡咯啉前体的N保护基团的性质。虽然像烷基这样的电子供体仅转化为所需的1,2,3-硫代噻唑的效率较低,但像甲基氨基甲酸酯这样的电子吸取取代基则给出了更高的产率。