1-Bromooctane → 2,7-Dibromo-9,9-di-n-octylfluorene

Participants

Reaction Conditions

Reaction Steps

In a 3-neck round-bottom flask (1,000 ml) equipped with a reflux condenser and an electronic thermometer, 2,7-dibromofluorene (64.8 g, 200 mmol, 1 eq.), 1-bromooctane (154.5 g, 800 mmol, 4 eq.), and tetrabutylammonium bromide (6.44 g, 20 mmol, 1/10 eq.) were dissolved in DMSO (dimethyl sulfoxide, 500 ml) under the protection of nitrogen. An aqueous solution of sodium hydroxide (32.0 g, 0.8 mol, 4 eq.) in water (40 ml) was dropped into the resulting light yellow solution with the speed of dropping controlled not to pass 60° C. The resulting brownish red reaction mixture was heated and stirred at 60° C. overnight. After it was allowed to cool down to room temperature, water (500 ml) was poured and the resulting mixture was stirred briefly and totally transferred into a separatory funnel (2,000 ml). The aqueous layer was separated and extracted with hexane (3×200 ml). The hexane extracts were combined, washed with 1 M hydrochloric acid (2×50 ml) and then with water (4×100 ml), and dried over MgSO4 (magnesium sulfate) overnight. The drying agent was filtered away and the filtrate was removed on a rotary evaporator. The reddish yellow residue was slowly poured into well-stirred methanol (1,000 ml) in an Erlenmeyer flask (2,000 ml). The resulting yellow precipitates were filtered out, crashed, washed with methanol (3×100 ml), and dried under suction and then in a vacuum oven at 40° C. and 3 in./Hg overnight. A white crystal (98.0 g) was collected with the yield of 89.3% with a melting point 63-65° C.

Provenance & Evidence