ChemicalBook CAS DataBase List 2,4,6-Trimethylphenylboronic acid

2,4,6-Trimethylphenylboronic acid synthesis

12synthesis methods

Product Name:2,4,6-Trimethylphenylboronic acid
CAS Number:5980-97-2
Molecular formula:C9H13BO2
Molecular Weight:164.01

576-83-0

5980-97-2

The general procedure for the synthesis of 2,4,6-trimethylphenylboronic acid from 2-bromo-1,3,5-trimethylbenzene was as follows: magnesium chips (60.27 mmol) were added to a dry three-necked round-bottomed flask along with anhydrous tetrahydrofuran (30 mL), and the suspension was stirred to form a suspension. Bromoisopropene (13.07 mmol) was slowly added and heated to initiate the formation of Grignard's reagent. Subsequently, 2-bromo-1,3,5-trimethylbenzene (32.02 mmol) was dissolved in anhydrous tetrahydrofuran (30 mL) and slowly added dropwise to the reaction system through a constant pressure dropping funnel. The reaction mixture was heated to reflux for 4.5 hours. Upon completion, the reaction system was cooled to -78 °C. Triethyl borate (111.66 mmol) was added dropwise over 15 minutes. After the dropwise addition was completed, the reaction system was allowed to slowly warm up to room temperature and stirring was continued for 5 hours. Subsequently, the reaction mixture was cooled to 0 °C, the reaction was quenched with 1 M hydrochloric acid solution and stirred for 2 hours. The reaction mixture was extracted three times with ether and the organic phases were combined. The organic phase was washed with saturated brine and dried over anhydrous sodium sulfate. After drying, the desiccant was removed by filtration and the filtrate was concentrated under reduced pressure to give the crude product. The crude product was recrystallized in benzene to give pure 2,4,6-trimethylphenylboronic acid (26.10 mmol, 58% yield). The product was characterized by 1H-NMR (400 MHz, CDCl3) and 13C-NMR (100 MHz, CDCl3) with the following data: 1H-NMR δ= 6.82 (s, 2H), 4.73 (brs, 2H), 2.33 (s, 6H), 2.26 (s, 3H); 13C-NMR δ= 139.64, 138.66, 127.99, 127.26, 22.89, 22.03, 21.12.

121-43-7
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576-83-0 Synthesis

576-83-0
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5980-97-2
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$10.00/1g

Yield:5980-97-2 85%

Reaction Conditions:

Stage #1: 2,4,6-trimethylphenyl bromidewith magnesium in tetrahydrofuran; for 3 h;Reflux;
Stage #2: Trimethyl borate in tetrahydrofuran at -78 - 20; for 12 h;

Steps:

General procedure of boronic acid synthesis

General procedure: A solution of 1 equiv. (10 mmol) mesitylbromide and 5 ml THF was addeddropwise to 1.2 equiv. (12 mmol, 0.30g) activated Mg turnings in 10 ml THF.After the reaction started, the mixture was refluxed for 3 hours. Then the reactionmixture was cooled to -78°C, and treated with 2 equiv. (20 mmol, 2.0g) offreshly distilled trimethylborate, and then the reaction mixture was allowed to warm up toroom temperature, and stirred overnight (12 hours). The reaction was quenched with 2 equiv.(20 mmol, 20 ml) 1M HCl-solution at 0 °C, then the mixture was stirred at rt. for two hours.The phases were separated and the aqueous phase was washed with 3x10 ml diethyl ether.The combined organic layer was washed with brine three times, dried over anhydrousNa2SO4, filtered off and evaporated to dryness. The resulted solid/oil was suspended in hexane,filtered off, washed with hexane 3 times and dried.

References:

Dorkó, éva;Kótai, Bianka;F?ldes, Tamás;Gy?m?re, ádám;Pápai, Imre;Soós, Tibor [Journal of Organometallic Chemistry,2017,vol. 847,p. 258 - 262] Location in patent:supporting information

576-83-0 Synthesis

576-83-0
257 suppliers
$27.00/25G

5980-97-2
266 suppliers
$10.00/1g

References

67-56-1 Synthesis