Selenium-containing heterocycles from ISO-selenocyanates:synthesis of 2-arylamino-selenazolo5,4-bpyridines

摘要

The reaction of 3-amino-2-chloropyridine (4) with aryl isoselenocyanates (2a-d) in refluxing 2-propanol gave the hydrochlorides of 2-arylaminoselenazolo5,4-bpyridines (7a-d) in good yield.The free bases (8a-d) were obtained after treatment with aqueous NaOH and recrystallization.A reaction mechanism via the intermediate selenourea derivatives (5) is most liekly.The structure of the 2-phenylamino derivative (8a) has been established by X-Ray crystallography.