Synthesis of bi- and tri-cyclic tetrazepinones

Abstract

Diazotization of N,N′-dialkyl-N-(o-aminophenyl) ureas 7,13 and 17 gave 3,5-dimethyl-3H-1,2,3,5-benzotetrazepin-4(5H)-one 8, 3-methyl-6,7-dihydro-1,2,3,5-tetrazepino[7,6,5-ij]quinolin-4(3H) one 14 and 3-methyl -6,7-dihydro[1,4]oxazino[4,3,2,5-ef]-1,2,3,5-benzotetrazepin-4-one 19. The structures of these bi- and tri-cyclic systems were confirmed by ¹H, ¹³C and ¹⁵N NMR data. X-Ray diffraction of compound 14 shows that the tetrazepinone ring is nonplanar.