新型三环系稠杂环［1,2,4］-三唑并［1,5-a］［1］-苯并氮杂及［1,2,4］-三唑并［1,5-a］-喹啉的合成

α-四氢萘酮的乙氧羰基腙(1)经LTA氧化, 得到α-偶氮-α-乙酰氧基化合物2. 在AlCl3作用下, 化合物2脱去乙酰氧基产生重氮正离子中间体3, 再经与腈的1,3-偶极环加成、 ［1,2］-迁移扩环、 碱性水解和与苦味酸作用, 得到新型［1,2,4］-三唑并［1,5 a］［1］苯并氮杂苦味酸盐6a~6c. 以2,3-二氢-1-茚酮为底物, 采用相同的合成路线, 合成了1,2,4-三唑并［1,5-a］-二氢喹啉苦味酸盐12a~12c.

Syntheses of Novel Tricyclic Fused Heterocycles:［1,2,4］Triazolo［1,5 a］［1］ benzazepine and ［1,2,4］ Triazolo［1,5 a］quinoline Derivatives

Oxidation of α tetralone ethoxycarbonylhydrazone(1) with lead tetraacetate afforded the bicyclic geminal ethyl azoester 2. On addition of equimolecular aluminum trichloride, the azocarbenium salt 3 was generated in situ as a reactive intermediate, which could be trapped by the cycloadditions to the triple bonds of nitriles giving 3H 1,2,4-triazolium salts. These initially cycloadducts couldn′t be isolated but underwent smooth 1,2-aryl-shift with concurrent ring enlargement and insertion of a nitrogen atom to the carbon skeleton to provide the tricyclic salts 4a—4c, from which the literature unprecedentate ［1,2,4］triazolo［1,5-a］［1］benzazepinium picrates 6a—6c were obtained in 23%~56% yields upon hydrolytic removal of the N ethoxycarbonyl group and subsequent treatment of the resulted heterocycles 5 with picric acid. Analogously, the novel 4,5 dihydro-［1,2,4］triazolo［1,5-a］quinolinium picrates(12a—12c) were prepared from 2,3 dihydro-1-indanone in moderate yields.