2-(Trifluormethoxy)phenylboronic acid synthesis
- Product Name:2-(Trifluormethoxy)phenylboronic acid
- CAS Number:175676-65-0
- Molecular formula:C7H6BF3O3
- Molecular Weight:205.93
64115-88-4
175676-65-0
The general procedure for the synthesis of 2-(trifluoromethoxy)phenylboronic acid from 1-bromo-2-(trifluoromethoxy)benzene was as follows: n-butyllithium (5.9 mL, 9.5 mmol) was slowly added dropwise to a solution of 1-bromo-2-(trifluoromethoxy)benzene (2 g, 8.2 mmol) in tetrahydrofuran (28 mL) at -78 °C and the reaction was stirred for 45 min. Subsequently, triisopropyl borate (2.58 mL, 11.1 mmol) was slowly added dropwise to the reaction mixture and the reaction system was slowly warmed to room temperature over 16 hours. Upon completion of the reaction, the reaction was quenched with water, the pH was adjusted to alkaline with 2 N NaOH solution and subsequently extracted with ethyl acetate. The aqueous phase was acidified to pH acidic with 2 N HCl solution, stirred for 1 h at room temperature and again extracted with ethyl acetate. The organic phases were combined, washed sequentially with water and saturated saline and dried over anhydrous sodium sulfate. After filtration, the organic phase was concentrated under reduced pressure to afford the target product 2-(trifluoromethoxy)phenylboronic acid (1.10 g, 65% yield) as a white solid. The product was confirmed by NMR hydrogen spectroscopy (CDCl3): δ 7.96 (dd, J = 7.2, 1.6 Hz, 1H), 7.53 (ddd, J = 9.1, 7.3, 1.8 Hz, 1H), 7.38 (td, J = 7.3, 0.7 Hz, 1H), 7.28 (d, J = 8.2 Hz, 1H), 5.25 (br s, 2H). Mass spectrometry analysis showed the molecular ion peak m/e 206.9 (M + 1)+.
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Yield: 65%
Reaction Conditions:
Stage #1:1-bromo-2-(trifluoromethoxy)benzene with n-butyllithium in tetrahydrofuran at -78; for 0.75 h;
Stage #2: with Triisopropyl borate in tetrahydrofuran at -78 - 20; for 16 h;
Stage #3: with hydrogenchloride;sodium hydroxide;watermore than 3 stages;
Steps:
1.3 EXAMPLE 1; 20 5-METHYL-L-R2&No.x0;-(TRIFLUOROMETHOXY)-L O L&No.x0;-BIPHENYL-3-YLL-LH-PYRAZOLE-3- carboxamide; Step 3: 2-(TRIFLUOROMETHOXY) PHENYLBORONIC ACID
n-Butyllithium (5.9 ml, 9.5 mmol) was added to a solution of 1-BROM-2- (trifluoromethoxy) benzene (2 g, 8.2 mmol) in tetrahydrofuran (28 ML) at-78°C and stirred for 45 minutes. Triisopropyl borate (2. 58 ml, 11.1 mmol) was added dropwise to the reaction mixture and the solution was slowly brought to room temperature over 16 hours. The reaction mixture was quenched with water, made basic with 2N NAOH and extracted with ethyl acetate. The aqueous solution was acidified with 2N HCI, stirred for 1 hour at room temperature and extracted into ethyl acetate. The organic layer was washed with water, brine solution and dried over sodium sulfate. It was filtered and concentrated to give the product (1.10 g, 65%) as a white solid. &No.x0;HNMR (CDCL3) ( 8, ppm): 7.96 (dd, J= 7.2, 1.6 Hz, 1 H), 7.53 (ddd, J = 9.1, 7.3, 1. 8 HZ, 1 H), 7.38 (td, J = 7.3, 0.7 Hz, 1 H), 7.28 (d, J = 8.2 Hz, 1 H), 5.25 (br s, 2H). MS: m/e 206.9 (M+1) +.
References:
MERCK & CO., INC. WO2004/92140, 2004, A1 Location in patent:Page 38
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64115-88-4
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175676-65-0
216 suppliers
$6.00/1g
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$12.00/5g
175676-65-0
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175676-65-0
216 suppliers
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