ChemicalBook CAS DataBase List 3-Bromo-9,9-dimethylfluorene

3-Bromo-9,9-dimethylfluorene synthesis

5synthesis methods

Product Name:3-Bromo-9,9-dimethylfluorene
CAS Number:1190360-23-6
Molecular formula:C15H13Br
Molecular Weight:273.17

2038-91-7

74-88-4

1190360-23-6

The general procedure for the synthesis of 3-bromo-9,9-dimethyl-9H-fluorene from 3-bromo-9H-fluorene and iodomethane was as follows: 37 g (152 mmol) of 3-bromo-9H-fluorene was dissolved in 600 ml of anhydrous DMSO in a dry flask and heated to a dry state. At room temperature, 43.9 g (457 mmol) of sodium tert-butanolate (NaOtBu) was added to the reaction system. At this point, the reaction mixture showed a blue suspension and the reaction temperature was adjusted so that the internal temperature reached 80°C. At this temperature, 64.8 g (457 mmol) of iodomethane was slowly added dropwise to the reaction system, and the rate of dropwise acceleration was controlled to ensure that the internal temperature did not exceed 90 °C (the dropwise acceleration time was about 30 min). After the dropwise addition, the reaction mixture was continued to be stirred for 30 min at an internal temperature of 80-90 °C. Subsequently, the reaction solution was poured into 1500 ml of ice water and stirred for about 20 minutes. The precipitated solid product was collected by diafiltration and washed sequentially with about 200 ml of water and methanol. Finally, 39 g (144 mmol) of the target product 3-bromo-9,9-dimethyl-9H-fluorene was obtained in 96% yield of the theoretical value; the purity of the product was 95% as analyzed by 1H-NMR.

2038-91-7 Synthesis

2038-91-7
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74-88-4
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1190360-23-6
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Yield:1190360-23-6 96%

Reaction Conditions:

with sodium t-butanolate in dimethyl sulfoxide at 80 - 90; for 0.5 h;

Steps:

3-bromo-9,9-dimethyl-9H-fluorene

37 g (152 mmol) of 3-bromo-9H-fluorene are dissolved in 600 ml of dry DMSO in a flask dried by heating. 43.9 g (457 mmol) of NaOtBu are added at room temperature. Let the blue suspension now have an internal temperature of 80 ° C. At this temperature, 64.8 g (457 mmol) of iodomethane are added dropwise to the purplish solution at a rate that does not exceed an internal temperature of 90 deg. C (duration: about 30 minutes). The batch is kept at an internal temperature of 80-90 ° C for an additional 30 minutes, then poured into 1500 ml of ice water and stirred for about 20 minutes. The precipitated solid is filtered off with suction and washed successively with about 200 ml of H2O and methanol. Yield: 39 g (144 mmol), 96% of theory; Purity: 95% by'H-NMR.

References:

KR2017/59015,2017,A Location in patent:Paragraph 0229-0231