Condensed 1,3,5-triazepines—II : The synthesis of 2,3-dihydro-1H-imidazo[1,2-a] [1,3,5]benzotriazepin-5(6H)-ones and -thiones

A method, based on the reaction of 1-(2-aminoaryl)-2-iminoimidazolidines 8 with phosgen, 1,1′-carbonydiimidazole and thiophosgene, carbon disulfide and 1,1′-thiocarbonyldiimidazole, respectively, has been devised for the synthesis of the title compounds. The compounds 8 are rearranged at elevated temperatures into the isomeric 2-amino-1-(2-amino-ethyl) benzimidazoles 11.