Hexane → (3,5-Dimethoxyphenyl)boronic acid

Under argon, to anhydrous tetrahydrofuran (9.0 mL) stirred in a dry ice-methanol bath was gradually added a 1.57 M solution of n-butyllithium in hexane (3.9 mL, 5.9 mmol), followed by the dropwise addition of a solution of 3,5-dimethoxyiodobenzene (713.0 mg, 2.70 mmol) in anhydrous tetrahydrofuran (5.0 mL). After the mixture was stirred for 20 minutes in the dry ice-methanol bath, triisopropyl borate (0.75 mL, 3.2 mmol) was added and the mixture was additionally stirred for 20 minutes. The reaction mixture was stirred at room temperature for 1 hour and concentrated under reduced pressure, then a 1.0 M aqueous sodium hydroxide (7.0 mL) was added to the residue. The resulting aqueous solution was washed with chloroform, acidified by adding concentrated hydrochloric acid, and extracted with chloroform. The organic layer was washed with brine, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure. The residue was recrystallized from chloroform-hexane to yield the title compound as a colorless crystalline powder (melting point: 159.0-161.0° C.)(367.0 mg, yield: 91%).

1. additionwas added
2. stirringThe reaction mixture was stirred at room temperature for 1 hour
3. concentrationconcentrated under reduced pressure
4. additiona 1.0 M aqueous sodium hydroxide (7.0 mL) was added to the residue
5. washThe resulting aqueous solution was washed with chloroform
6. additionby adding concentrated hydrochloric acid
7. extractionextracted with chloroform
8. washThe organic layer was washed with brine
9. dry with materialdried over anhydrous sodium sulfate
10. concentrationconcentrated under reduced pressure
11. customThe residue was recrystallized from chloroform-hexane

ORD record

ord-8b06a3384ac242e0bedec3e1580b616c

Source dataset

uspto-grants-2004_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06706703B2