New heterocyclic selenenamides: 1,2,4-benzoselenadiazin-3(4H)-ones and 1,3,2-benzodiselenazoles

Two groups of selenium-containing heterocycles having new, unique 1,2,4-benzoselenadiazine and 1,3,2-diselenazole ring systems with an endocyclic selenenamide C–N moiety are presented. The first type was obtained by oxidative cyclization of 2,2′-diselenobis(phenylureas) and the second type by the reaction of 1,2-di(bromoseleno)benzene with primary amines.