Highly efficient synthesis of 5-benzyl-3-aminoindazoles (original) (raw)

Cyanogen-Bromide-Mediated and Methyl-Chloroformate-Mediated Synthesis of Some [3]Benzazonino[8,7,6- abc ]Carbazole, [3]Benzazecino[9,8,7- abc ]Carbazole, Naphth[1,8,7- def ]Azonine and Naphth[1,8,7- def ]Azecine Derivatives

Australian Journal of Chemistry, 1986

Reaction of 7,8-dimethoxy-1,4,5,9,13c,13d-hexahydro-2H-indolo [3′,2′:4,5] indolo [1,7,6-aji] isoquinoline (4a) and 8,9-dimethoxy- 1,2,3,5,6,10,14c,14d-octahydro-indolo[3′,2′:3,4] naphtho [2,1,8-ija] quinolizine (4b) with cyanogen bromide in the presence of potassium carbonate afforded the elimination products 7,8-dimethoxy-1,2,3,4,5,9- hexahydro [3] benzazonino [8,7,6-abc]carbazole-3-carbonitrile (5a) and 8,9-dimethoxy-2,3,4,5,6,10-hexahydro-1H-[3] benzazecino [9,8,7-abc]carbazole-4-carbonitrile (5b) in 4% and 88% yield respectively; 7- (2-bromo)ethyl-1,2-dimethoxy-4,5,6,6a,7,12-hexahydroisoquino[8,1-ab ]carbazole-6-carbonitrile (6a) was also isolated in 20% yield from the former reaction. Products of analogous structure were also obtained from (4a,b) when methyl chloroformate was used in place of cyanogen bromide. Reaction of (4b) with cyanogen bromide in the presence of water and magnesium oxide afforded the solvolysis product 14d-hydroxy-8,9-dimethoxy-2,3,4,5,6,10,14d,14d-octahyd...