反应详情

温度

-80 °C

A solution of n-butyllithium in hexane (1.7 mL of 2.5 M, 4.25 mmol) is added to a stirred solution of 4-(3-bromo-4-methoxyphenyl)pyridine (Example 1b; 1.06 g, 4 mmol) and triethylborate (0.62 g, 4.2 mmol) in dry tetrahydrofuran (20 mL) at −85° C. under an argon atmosphere. The mixture is stirred for 15 min at −80° C., then treated with a saturated aqueous solution of ammonium chloride (60 mL) and extracted with ethyl acetate (2×80 mL). The combined extracts are dried (Na2SO4), filtered and the solvent is evaporated off under reduced pressure to yield the crude product which is purified by recrystallisation from ethyl acetate-hexane to give 2-methoxy-5-(pyridin-4-yl)phenylboronic acid as a beige crystalline solid, m.p. 194-200° C. and having the following physical characteristics:

1. extractionextracted with ethyl acetate (2×80 mL)
2. dry with materialThe combined extracts are dried (Na2SO4)
3. filtrationfiltered
4. customthe solvent is evaporated off under reduced pressure
5. customto yield the crude product which
6. customis purified by recrystallisation from ethyl acetate-hexane