2-Aminobenzophenone semicarbazones (II) or 2-aminobenzophenone phenylhydrazones (III) were cyclized to 3,7-disubstituted 5-phenyl-2,3-dihydro-1H-benzo[e]-1,3,4-triazepines (IV) by treating them with paraformaldehyde. On the other hand, 3,7-disubstituted 2-oxo-5-phenyl-2,3-dihydro-1H-benzo[e]-1,3,4-triazepines (V) were prepared by the fusion of II at 190–195°C or by the treatment of III with phosgene. In the latter reactions, 1-carboxy derivatives (VI) of V were obtained by using two equimolar amounts of phosgene. Vf was treated with sodium ethoxide to give a ring-cleavage product, 5-chloro-2-ethoxycarbonylaminobenzophenone phenylhydrazone (VIIIf), which was then fused to afford 6-chloro-1,2-dihydro-2-oxo-4-phenylquinazoline (VIIb).

No abstract

The reaction of 2-aminobenzophenones with aliphatic acids, such as acetic acid, propionic acid, n-butyric acid, and bromoacetic acid, in the presence of polyphosphoric acid afforded 6-substituted 2-anilino-4-phenylquinoline derivatives in fairly good yields. Some of these quinolines were acetylated in the usual way, and the products, 2-(N-acetylanilino) quinolines, were treated with sodium ethoxide to give 1-quinolyl-2(1H)-quinolone derivatives. 2-Amino-5-chlorobenzophenone (Ic) reacted with an equimolar amount of 2-acetamido-5-methylbenzophenone to give 2-(2-benzoyl-4-methylanilino)-6-chloro-4-phenylquinoline, which was also obtained from the reaction of 2,6-dichloro-4-phenylquinoline with Ib in the presence of copper powder. It was found that the reaction mechanism in the formation of 2-anilinoquinolines is similar in type to that in Friedländer’s reaction. Furthermore, the structures of the 2-anilinoquinolines are discussed on the basis of our NMR spectral study.

Die Aminobenzophenone (I) reagieren mit den Carbonsäuren (II) zwischen 105 und 180°C in Gegenwart von Polyphosphorsäure zu den Chinolinen (III) (7 1 ‐94% Ausbeute).

Die Benzophenonsemicarbazone (II) cyclisieren sich mit Paraformaldehyd in Xylol in 15 bzw. 13%iger Ausbeute zu den Benzotriazepinen (I) und mit Phosgen zu den Benzotriazepinonen (III) (20‐25% Ausbeute).