Hydrochloric Acid → 2,6-Dimethoxy-4-methoxymethylphenylboric acid

Temperature

0 °C

Under cooling in an dry ice-acetone bath in nitrogen flow, to a solution of 2-bromo-1,3-dimethoxy-5-(methoxymethyl)benzene (20.0 g, 76.6 mmol) in tetrahydrofuran (200 mL) was added a solution (50.9 mL, 80.4 mmol) of 1.58Mn-butyllithiumin hexane, and the reaction mixture was stirred for 30 minute. Then, to the reaction mixture was added a solution of trimethoxyborane (8.75 g, 84.2 mmol) in tetrahydrofuran (20 mL), and the reaction temperature was raised up to 0° C. under stirring. To the reaction mixture was added 1N hydrochloric acid (200 mL), and the reaction mixture was stirred for 30 minutes at room temperature. After the reaction, to the reaction mixture was added toluene (200 mL) and an organic layer was separated, then, the remaining aqueous layer was further extracted with toluene (100 mL). Combined organic layers were washed with water (100 mL), and the solvent was concentrated under reduced pressure. The resulting residue was dissolved in t-butyl methyl ether (75 mL), the reaction mixture was stirred for 30 minutes. Then, to this was added heptane (223 mL), and the mixture was further stirred for 2 hours. A precipitate was filtrated, and the precipitate was washed with a t-butyl methyl ether-heptane mixed solution (1:3, 3.75 mL), and dried at 40° C. for 24 hours to obtain 12.4 g of a title compound (yield: 71.8%).

1. temperatureUnder cooling in an dry ice-acetone bath in nitrogen flow
2. stirringunder stirring
3. stirringthe reaction mixture was stirred for 30 minutes at room temperature
4. customAfter the reaction
5. customan organic layer was separated
6. extractionthe remaining aqueous layer was further extracted with toluene (100 mL)
7. washCombined organic layers were washed with water (100 mL)
8. concentrationthe solvent was concentrated under reduced pressure
9. dissolutionThe resulting residue was dissolved in t-butyl methyl ether (75 mL)
10. stirringthe reaction mixture was stirred for 30 minutes
11. additionThen, to this was added heptane (223 mL)
12. stirringthe mixture was further stirred for 2 hours
13. filtrationA precipitate was filtrated
14. washthe precipitate was washed with a t-butyl methyl ether-heptane mixed solution (1:3, 3.75 mL)
15. customdried at 40° C. for 24 hours

ORD record

ord-83e41c4e86e548daab181c183984e632

Source dataset

uspto-grants-2010_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07858809B2