The new heterocyclic derivatives 3-methyl-1-phenyl-3,4,5,10-tetrahydro- 1H-[1,2]oxazepino[6,5-b]-indole (5c), 6-methyl-4-phenyl-4,6,7,8- tetrahydrothieno[2,3-e][1,2]oxazepine (6f), and 3-methyl-1-phenyl- 1,3,4,5-tetrahydro[1]benzothieno[3,2-e][1,2]oxazepine (7c) were prepared in good yield by thermal Meisenheimer rearrangement of the corresponding tertiary amine N-oxide precursors. No such rearrangement occurred on heating the N-oxides of the fused bicyclic systems 2,3,11,12-tetramethoxy-5,8,9,13b-tetrahydro-6H-dibenzo[a,h]quinolizine (3) and 8,9-dimethoxy-1,2,3,5,6,10b-hexahydropyrrolo[2,1-a]isoquinoline (4). The reduction of (5c), (6f) and (7c) with zinc in acetic acid is also described.

The heterocyclic derivatives, 8,9-dimethoxy-3-methyl-1-phenyl-3,4,5,6- tetrahydro-1H-2,3-benzoxazocine(3a) and 9,10-dimethoxy-3-methyl-1- phenyl-1,3,4,5,6,7-hexahydro-2,3-benzoxazonine (3b),examples of two new ring systems, have been prepared by Meisenheimer rearrangement of the corresponding 2-benzazepine and 2-benzazocine N-oxide derivatives (2a) and (2b). The Bischler-Napieralski-type cyclization reaction was used in the preparation of the tertiary amine precursors of these N-oxides reaction conditions for the cyclization were critical and phosphorus oxychloride in refluxing butanenitrile was found to give the best yields of the seven- or eight-membered cyclic imine intermediates. Reductive cleavage of the benzoxazocine derivative (3a) with zinc in acetic acid followed by N-methylation gave the expected product, [2-{3- (dimethylamino)propyl}-4,5-di-methoxyphenyl]phenylmethanol (12). The crystal and molecular structure of (3a) has been determined by X-ray crystallographic analysis.

Cyclisierung der Amide (I) (Darstellung von (Ib) ist beschrieben), Methoiodierung der Produkte (II) [ ‐+ (III)] und nachfolgende Reduktion liefern die Heterocyclen (IVa) und (IVb), deren N‐Oxide (IVc), (IVd) sich spontan (IVd) bzw. beim Erhitzen in Acetonitril (IVc) in die Titelverbindungen (Va) (Röntgenstrukturanalyse: P21/n(C2h5 ); Z=4) bzw. (Vb) umlagern.

Das N‐Oxid (II) der Verbindung (I) lagert sich beim Erhitzen in das Oxazepinoindol (III) um; analog werden die Heterocyclen (IV) und (V) gewonnen.

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