在此,我们报告了 H 2 O 2介导的 1,2,4-噻二唑衍生物在室温下无金属条件下以乙醇为唯一溶剂的合成。各种底物可以顺利进行反应,提供预期产物的预期产率。此外,目标产物是通过过滤或萃取代替柱层析获得的,在纯化过程中需要大量的有机溶液和硅胶。所开发的合成方法可用于大规模制备 1,2,4-噻二唑衍生物作为农用化学品、药物和功能材料。
An efficient synthesis of 3-substituted-5-arylamino-1,2,4-thiadiazoles through intramolecular oxidative S–N bond formation of imidoyl thioureas by phenyliodine(III) bis(trifluoroacetate) is reported. The protocol features a metal-free approach, broad substrate scope, very short reaction times, good to excellent yields, and simple starting materials.
has been developed by the reaction of isothiocyanates with amidines. This protocol which is free of metal, catalyst and iodine involves O2 oxidative S–N bond formation for the synthesis of various 5-amino-1,2,4-thiadiazole derivatives with excellent to good yields. High regioselectivity, mild reaction conditions, broad substrate scope and good functional group tolerance are the highlights of the report
A facile and efficient protocol for the synthesis of 3-substituted 5-amino-1,2,4-thiadiazoles has been developed through the electro-oxidative intramolecular dehydrogenative N-S bond formation of imidoyl thioureas. Various 1,2,4-thiadiazole derivatives were synthesized in good to excellent yields with broad substrate scope and excellent functional group tolerance under catalyst- and oxidant-free electrolytic
A simple and practical method for the one‐potsynthesis of 3‐aryl‐5‐amino‐1,2,4‐thiadiazoles from imidates and thioureas has been developed. The protocol proceeds through sequential base‐mediated nucleophilic addition‐elimination reactions and an I2‐mediated oxidative coupling for the N–S bond formation.
A continuous flow synthesis and derivatization of 1,2,4-thiadiazoles
作者:Marcus Baumann、Ian R. Baxendale
DOI:10.1016/j.bmc.2017.01.022
日期:2017.12
A continuous flowprocess is presented that enables the efficient synthesis and derivatization of 1,2,4-thiadiazole heterocycles. Special attention was given to the safe handling of the versatile yet hazardous trichloromethane sulfenylchloride reagent including its in-line quenching in order to eliminate malodourous and corrosive by-products. Based on this flow method gram quantities of 5-chloro-3-phenyl-1