2,7-Dibromo-9,9-dimethylfluorene

White solid

(1) 2, 7-dibromofluorene (9.72 g, 30 mmol), tetra-n-butylammonium bromide (0.08 g, 0.25 mmol), methyl iodide (12.8 g, 90 mmol) NaOH solution 10mL, DMSO 120mL, added to 250mL single-necked flask, ultrasonic reaction 5h (100W), after the reaction was poured into 500mL of water, stirred for 30min after suction filtration, washed with water and dried to give a pale yellow solid 10.5g, yield 99 percent.Step 2: At room temperature, 2, 7-dibromofluorene (9.72 g, 30 mmol) and tetra-n-butylammonium bromide were added to the reactor. (0.08g, 0.25mmol), methyl iodide (12.77g, 90mmol), 10percent NaOH solution, 10mL, DMSO 120 mL, ultrasonic reaction for 5 h, then add 500 mL of water to stop the reaction, stirring, suction filtration, washing with water, and drying to obtain Intermediate 1-2 (10.46 g, 99percent).In a stream of argon, 32 g (0.1 mol) of 2, 7-dibromofluorene, 27 g (0.24 mol) of t-butoxypotassium, and 500 mL of DMSO were added to a 3-L three-necked flask, and the reaction system was cooled to 5°C. Subsequently, 34 g (0.24 mol) of methyl iodide were slowly dropped to the resultant, and then the whole was stirred overnight. After the completion of the reaction, water was added to the resultant, and an organic layer was extracted with ethyl acetate and washed with a saturated salt solution. After the washed product had been dried with magnesium sulfate, the solvent was removed by distillation with a rotary evaporator, whereby a coarse reaction product was obtained. The product waspurified by meansof column chromatography (silica gel (hexane solvent) : ethyl acetate = 95 : 5), whereby 34 g of Intermediate 6 (white crystal, 98percent yield) as a target were obtained.Synthesis (4-1) Synthesis of Intermediate 7 Into a 3 liter three-necked flask, 32 g (0.1 mole) of 2, 7-dibromofluorene, 27 g (0.24 moles) of t-butoxypotassium and 500 ml of DMSO were placed under the stream of argon, and the reaction system was cooled at 5° C. After 34 g (0.24 moles) of methyl iodide was slowly added dropwise, the resultant mixture was stirred for one night. After the reaction was completed, water was added, and the organic layer was separated by extraction with ethyl acetate, washed with a saturated aqueous solution of sodium chloride and dried with magnesium sulfate. The solvent was removed by distillation using a rotary evaporator, and a crude reaction product was obtained. The crude reaction product was purified in accordance with the column chromatography (silica gel; hexane:ethyl acetate=95:5), and 34 g of Intermediate 7 of the object compound was obtained (white crystals; the yield: 98percent).2, 7-dibromofluorene (2.0 g, 6.2mmol), dimethyl sulfoxide (0.2 ml), benzyltriethylammonium chloride (0. 07 g, 0.3 mmol), and a 50 wtpercent aqueous solution of NaOH (2 g) were added to a flask. Next, iodomethane (2.2 g, 15 mmol) was dropped to the mixture, and the whole was stirred for 30 minutes. Water (100 mL) and toluene (100 mL) were added to the reaction liquid in such a manner that an organic layer would be separated. The organic layer was washed with a saturated brine, and was then dried with anhydrous magnesium sulfate. The resultant was concentrated under reduced pressure by using a rotary evaporator, and then the residue was purified by means of silica gel column chromatography, whereby Intermediate 4-1 was obtained (amount 2.0 g, yield 94 percent).These compounds were obtained following an essentially similar procedure. An illustrative example is provided for 8: 2-bromofluorene (4.90 g, 0.02 mol) was dissolved in anhydrous THF (100 mL) in a three-necked round-bottom flask fitted with a magnetic stirrer, a condenser and a N2, 7-Dibromofluorene (13.2 g, 40 mmol), potassium hydroxide (10 g, 179 mmol) were stirred in dimethylsulfoxide (80 mL). Iodomethane (12.5 g, 88 mmol) in dimethylsulfoxide (80 mL) was added dropwise for 8 h. The reaction was stirred at room temperature for 24 h and then poured into 500 mL water. The product was extracted with dichloromethane and the combined organic layers were evaporated to dryness. The crude product was recrystallized in ethanol to give compound 2 as yellow solid (12.11 g, 84percent).

Pharmaceutical intermediates are also important intermediates for the synthesis of optoelectronic materials

Molecular Weight:352.06
XLogP3:5.8
Exact Mass:351.92853
Monoisotopic Mass:349.93058
Heavy Atom Count:17
Complexity:271
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes