文摘
Interaction of 5-indazolyldiazonium chloride 2 with 2-hydroxymethylidene cyclohexanone 5 and N-benzyl-3-hydroxymethylidene-4-piperidone 6 under the conditions of Japp–Klingemann reaction, followed by Fischer-indolization of the resulting hydrazones, formed the 5,7,8,9-tetrahydropyrazolo[4,3-b]carbazol-6(1H)-one 9 and 9-benzyl-5,7,8,9-tetrahydropyrido[2′,3′:4,5]pyrrolo[2,3-f]indazol-6(1H)-one 10, respectively. Pfitzinger reaction of 9 and 10 with isatin in alkali afforded the corresponding quinoline carboxylic acid derivatives 12 and 13, respectively.