Cyclization of 4-Phenylthiosemicarbazide with Phenacylbromide Revisited. Formation of 1,3,4-Thiadiazines and of Isomeric 1,3-Thiazoles
作者:Wolf-Diethard Pfeiffer、Dieter Junghans、Ashot S. Saghyan、Peter Langer
DOI:10.1002/jhet.2007
日期:2014.7
cyclization of 4‐phenylthiosemicarbazide with phenacylbromide, carried out in refluxing ethanol, afforded 1,3,4‐thiadiazine 1 as the major product. In contrast to a previous report, 2‐phenylimino‐4‐phenyl‐2,3‐dihydro‐1,3‐thiazol‐3‐amine (2) and not 2‐hydrazono‐3,4‐diphenyl‐2,3‐dihydro‐1,3‐thiazole (8) was formed as a side‐product. This product is the main product when the reaction is carried out in concentrated
在回流的乙醇中,将4-苯基硫代氨基脲与苯乙酰胺环化,得到1,3,4-噻二嗪1作为主要产物。与以前的报告相反,2-苯基亚氨基-4-苯基-2,3-二氢-1,3-噻唑-3-胺(2)而不是2-肼基-3-3,4-二苯基-2,3-二氢-1,3-噻唑(8)是副产物。当反应在浓盐酸中进行时,该产物是主要产物。我们的发现通过异构体产物的独立合成以及对它们反应性的深入研究得到独立证实。重要的是要注意,具有卤代酮的硫代氨基脲的环化产物分布在很大程度上取决于取代模式和反应条件。