Mono-, di-, and trisubstituted 2-aminonicotinonitriles 8, 13, 14, and
19 are prepared from ketonic Mannich-bases hydrochlorides 4 . HCl, eno
nes 12, beta-aminovinylketones 17, 3 aminoacroleines 18, vinamidinium
perchlorates 21, and 3,3 diaminoacrylonitrile (3). generated in situ.
3 is further reacted with 4 . HCl in the presence of ammonium acetate
to yield the tetrahydro-1.8 naphthyridines 10.