SYNTHESIS OF 5H-PYRIDO[2,3-C]-2-BENZAZEPI NES

The title compounds can be obtained by two differend ways: Ring closur e of 2-benzazepine enaminonitrile 1 and the C-2-building blocks 2, 7 a nd 8 gives rise to the title compounds 6, 9 and 10. - The second way s tarts with Wolff-Kishner-reduction of the 2-amino-3-benzoylpyridines 1 6a,b to the 2-amino-3-benzylpyridines 18a,b. Benzoylation of 18a,b lea ds to the dibenzoylated compounds 20 and 21, respectively, which can b e transformed to the monobenzoylated pyridines 22 resp. 23. Applying t he Bischler-Napieralski-reaction on 22a,b and 23a,b leads to the 5H-py rido[2,3-c]2-benzazepines 24a,b and 25a,b. By means of H-1-, C-13- and N-15-NMR data it is demonstrated that ethyl benzoylcyanacetimidate (1 2a) exists as benzoylketene-O,N-acetal 12a AE.