53356-70-0

18992-65-9

15 g of Intermediate Int-1 from the previous step was mixed with 100 ml of dichlorobenzene and 86.5 g of triphenylphosphine was added under stirring conditions. The reaction mixture was heated to 180°C and maintained at this temperature for 24 hours, followed by cooling to room temperature. After completion of the reaction, the concentrate was dried under reduced pressure and 100 ml of petroleum ether was added. The mixture was heated to boiling state and filtered while hot. The filter cake was washed with petroleum ether and the filtrate was concentrated under reduced pressure. Finally, the residue was purified by silica gel column chromatography to afford 11.5 g of 2,7-dimethylcarbazole Int-2 as a yellow solid product in 89% yield.