Fischer Indolization and Its Related Compounds. XVI. Vilsmeier-Haack Reaction of N-Methyl-1,2,3,4-tetrahydrocarbazole Derivatives

概要

論文の詳細を見る
Vilsmeier-Haack reaction of 6-chloro-1,2,3,4-tetrahydro-9-methylcarbazole (1b) with 3 mol eq. POCl_3 at 70°gave three compounds, 6-chloro-1,2,3,4-tetrahydro-9-methyl-carbazole-1,1-dicarboxaldehyde (4), 6-chloro-3,4-dihydro-9-methylcarbazole-1 (2H)-one (5b), and 6-chloro-1,2,3,4-tetrahydro-1-hydroxy-9-methylcarbazole-1-carboxaldehyde (6), while no 4a-formylated product^1) was obtained. On the other hand, the reaction of the same compound (1b) with 1.3 mol eq. POCl_3 at 100°gave 6-chloro-1,2,3,4-tetrahydro-9-methyl-carbazole-1-carboxaldehyde (20), 5b, 6-chloro-1,2,3,4-tetrahydro-9-methylcarbazole-7-carboxaldehyde (3b), and an aromatized compound, 6-chloro-1,9-dimethylcarbazole-3-carboxaldehyde (2b). The formation mechanism of the aromatized compound (2b) is considered to involve elimination of a dimethylamino group and formation of 6-chloro-1,9-dimethylcarbazole (21) as an intermediate.
公益社団法人日本薬学会の論文
1981-03-25