12H- [1] benzothieno [2,3-a] carbazole

In a 3L flask,104.0 g (0.33 mol) of N-(2-chlorophenyl)dibenzo[b,d]thiophen-4-amine, 7.54 g (33.6 mmol) of palladium acetate, 328.26 g(1.0 mol) cesium carbonate, and 24.7 g (67.17 mol)Tricyclohexylphosphine-tetrafluoroborate were mixed with 1.1 L of N, N-dimethylacetamide. The mixture was heated and refluxed under a stream of nitrogen for 12 hours. When the reaction was over, After volatilizing and removing the solvent. The product was added to 2L of methanol. The crystallized solid was filtered and dissolved in dichlorobenzene. After filtration over silica gel/Celite after removal of the appropriate amount of organic solvent, recrystallization from methanol gave 12H- [1] benzothieno [2,3-a] carbazole (81.0 g, yield 88%).