3-Bromo-4-nitroquinoline 1-oxide (1) reacted with 2-methylaminoethanol
, 1-amino-2-propanol and ethylenediamine to give the corresponding 3-a
mino-4-nitroquinoline 1-oxides (2, 4 and 7), which readily underwent t
he intramolecular cyclization, upon heating with Ac2O in DMF, to affor
d the morpholino[2,3-b]quinolines (3 and 6) and the piperazino[2,3-b]q
uinoline (8). The reaction of 1 with N,N'-dimethylethylenediamine affo
rded directly the piperazinoquinoline (10), and that with 2-aminoethan
ethiol gave the thiomorpholino[2,3-b]quinoline (11) and its 10-oxide (
12).