Application background and overview of 1-naphthylboronic acid pinacol ester
1-Naphthylboronic acid pinacol ester is an organic ester compound, which can be used as a pharmaceutical synthesis intermediate.
Application structure of 1-naphthylboronic acid pinacol ester
Application and preparation of 1-naphthylboronic acid pinacol ester
1-Naphthylboronic acid pinacol ester is prepared as follows:
In a 250mL three-necked flask, add 1-bromonaphthalene (5.0g, 17.8mmol), bipinalcohol borate (9.0g, 35.6mmol), and Pd(dppf)Cl2 (290mg, 0.40mmol), anhydrous CH3COOK (5.2g, 53.4mmol) and 150mL tetrahydrofuran (THF), deoxygenated by nitrogen, and magnetically stirred at 80°C for 24h. After the reaction is completed, most of the THF is evaporated, and the residue is poured into 100 mL of water, extracted with dichloromethane (DCM) (3 × 25 mL), the organic phases are combined, and dried with anhydrous MgSO4 Leave overnight, filter, and remove the solvent under reduced pressure. The crude product is eluented with a mixed solvent of petroleum ether-dichloromethane (PE-DCM, V/V, 5/1), and the adsorbent is 200-300 mesh silica gel. After column chromatography separation, 1.92g of white solid product was obtained, with a yield of 78.0%. 1HNMR (MHz, CDCl3, TMS), δ (ppm): 8.76 (d, J=8.0Hz, 1H), 8.08 (d, J=6.4Hz, 1H), 7.93 (d, J=8.4Hz, 1H), 7.83 (d, J=8.0Hz, 1H), 7.53-7.45 (m, 3H), 1.43 (s, 12H) .
Applications of 1-naphthylboronic acid pinacol ester
1-Naphthylboronic acid pinacol ester can be used as a pharmaceutical synthesis intermediate. If the following reaction occurs:
The specific reaction steps are:
1) Add (4-(bis(4-bromophenyl)amino)phenyl)methanol (5.10g, 11.8mmol), 15methyltetrahydrofuran 0mLTHF, 1,6-di Hexyl bromide (14.33g, 58.8mmol), NaH (1.5g, 62.5mmol). Deoxygenate with nitrogen and react at room temperature for 24 hours. After the reaction, most of the solvent is evaporated and the remaining residue is poured into 50 mL of water.�, wash away unreacted NaH, extract with DCM (3×35mL), combine the organic phases, dry with anhydrous MgSO4 overnight and then filter, spin off the solvent under reduced pressure, and the crude product is treated with PE- DCM (V/V, 5/1) was used as the eluent, and the adsorbent was 200-300 mesh silica gel. The product was separated by column chromatography to obtain 5.60g of the product, with a yield of 79.6%.
2) Add the compound obtained in step 1 (2.80g, 4.7mmol), 1-naphthylboronic acid pinacol ester (3.54g, 10.8mmol), and tetrakis(triphenylphosphorus)palladium into a 250mL round-bottomed flask. (1 Sodium bicarbonate 62 mg, 0.14 mmol), 100 mL THF, 10 mL 2 mol/L K2CO3 solution. Deoxygenate with nitrogen and react at 80°C for 22 hours. After the reaction is completed, most of the THF is evaporated. The residue is poured into 50 mL of water, K2CO3 is washed away, and extracted with DCM ( 3×35mL), combine the organic phases, dry with anhydrous MgSO4 overnight and filter, remove the solvent under reduced pressure, and elute the crude product with PE-DCM (V/V, 2/1) The adsorbent is 200-300 mesh silica gel, and the product is separated by column chromatography to obtain 1.64g of white powder product with a yield of 71.1%. 1HNMR (MHz, CDCl3, TMS), δ (ppm): 8.04 (d, J=7.9Hz, 2H), 7.91 (d, J=7.5Hz, 2H), 7.85 (d, J=8.0Hz, 2H), 7.55-7.42 (m, 12H), 7.34-7.28 (m, 8H), 4.50 (s, 2H), 3.54 ( t, J=6.4Hz, 2H), 3.41 (t, J=6.8Hz, 2H), 1.90-1.85 (m, 2H), 1.69-1.64 (m, 2H), 1.47-1.44 (m, 4H).
