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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of 2-bromo-1,3-dimethoxy-5-(methoxymethyl)benzene (20.0 g, 76.6 mmol) in tetrahydrofuran (200 mL) which had been cooled in a dry ice-acetone bath was added 1.58M n-butyllithium in hexane (50.9 mL, 80.4 mmol) under a nitrogen stream, and the reaction mixture was stirred for 30 minutes. A solution of trimethoxyborane (8.75 g, 84.2 mmol) in tetrahydrofuran (20 mL) was then added to the reaction mixture, and the reaction temperature was increased to 0° C. while stirring. After adding 1N hydrochloric acid (200 mL) to the reaction mixture, it was stirred for 30 minutes at room temperature. After the reaction terminated, toluene (200 mL) was added to the reaction mixture and the organic layer was separated off, after which the aqueous layer was extracted with toluene (100 mL). The combined organic extracts were washed with water (100 mL) and then concentrated under reduced pressure. The residue was dissolved in tert-butyl methyl ether (75 mL) and the reaction mixture was stirred for 30 minutes, after which heptane (223 mL) was added thereto and the reaction mixture was further stirred for 2 hours. The precipitate was filtered out and washed with a mixed solution of tert-butyl methyl ether and heptane (1:3, 3.75 mL), and then dried at 40° C. for 24 hours to afford 12.4 g of the title compound (71.8% yield).

Herkunft & Nachweise