An Efficient Synthesis of 1,2,4Triazolo3,2-d1,5benzoxazepin-2-thiones,a Kind of Novel Tricyclic O,N-Heterocycles

摘要

A series of novel tricyclic O,N-heterocycles, [1,2,4]triazolo[3,2-d][1,5]benzoxazepin-2-thiones 7 were achieved via acid-induced ring closure of the geminal arylazo isothiocyanate compounds 5 which were derived from substituted chroman-4-ones, followed by feasible ring expansion with simultaneous insertion of the nitrogen atom into the carbon skeleton. The X-ray crystal structure of 7d was also described.