Synthesis, structure and transformations of 2-iminoimidazolidines into novel fused heterocyclic ring systems

Reaction of 2-chloro-4,5-dihydroimidazole (1) with 2-aminobenzylamines (2a-d) afforded 2-[(imidazolidin-2-ylideneamino)methyl]anilines (3a-d) which upon treatment with carbon disulfide gave 2,3-dihydro-12H-imidazo[2',1':4,5][1,3,5]thiadiazino[2,3-b]quinazolin-5-thiones (4a-d) and 3,4-dihydro-1H-quinazolin-2-thiones (5a-c). Analogous reaction of 1 with 2-aminobenzyl alcohol (6) led to the formation of [2-(4,5-dihydrol 1H-imidazol-2-ylamino)phenyl]methanol hydrochloride (7) which was transformed into 1-(4H-3,1-benzoxazin-2-yl)imidazolidin-2-thione (8).