Nitrogen bridgehead compounds. Part 88. Synthesis of 3H,7H-[1,4]diazepino[3,4-b]quinazoline-3,7-diones

3H,7H-[1,4]Diazepino[3,4-b]quinazolone-3,7-diones 9, 11 were synthesized starting from 2-(1-bromo-ethyl)quinazolin-4(3H)-ones 3 and 17 via 2-[1-(4-methoxyphenylamino)ethyl]quinazolin-4(3H)-ones 4 and 18. Cyclization of 3-[2-(1-bromoethyl)-4-oxo-3,4-dihydroquinazolin-3-yl)propionic acid 14 by the action of triethylamine provided the first representative of the tricyclic 7H-[1,4]oxazepino[3,4-b]quinazoline-3,7-dione system, compound 15. The new tricyclic derivatives 9, 11 and 15 are characterized by uv, ir and 1H nmr spectroscopy.