Benz azocine

Some other ring expansions involving the intramolecular amino Claisen rearrangement of vinylarylaziridine [ 123], the Diels-Alder reaction of indoles with acetylene derivative [124-127] and the dibromocarbene insertion into quinoline enol ethers [ 128] have been used to prepare 1-benzazepines. On the other hand, treatment of 3-chloro-3-phenyl-l,2,3,4,5,6-hexahydro-l-benz-azocin-2-ones with piperidine causes a ring contraction to give 2-phenyl-2-(l-piperidinylcarbonyl)-2,3,4,5-tetrahydro-l//-l-bcnzazepines in an excellent yield [23]. 

Only two examples of the synthesis pyrimidoazocines have been described. In Ref. 82JHC1257, a three-stage synthesis of a new heterocycle system, pyrimido[5,4-c]benz[l]azocine, has been proposed. Condensation of 4-methyl-2-phenyl-5-pyrimidincarboxylate (112) with 3,4-dimethoxy-6-nitrobenzaldehyde (113) led to the substituted alkene 114, which, after catalytic hydrogenation of the nitro group on Raney nickel and subsequent intramolecular cyclization of product 115, was converted into pyrimidobenz[l]azocine 116 (Scheme 32). 

Thieno[4,3,2-/g]benz[l]azocine 187 is produced in high yield (79MI397) from oxime 186 by Beckman rearrangement in PPA. Transformations of amide and thioamide groups of azocines 187 and 188, lead to derivatives 189-192, as shown in Scheme 52. 

X-ray diffraction data confirmed the structure of the (5>. The relative configuration, in similar such systems, was determined by H and C NMR <89AP(322)21>. 

The total synthesis of mitomycins by Kishi and co-workers was based on the transannular closure of a benz[b]azocine [11]. This approach has been investig-... 

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