Triisopropyl borate → (5,6,7,8-Tetrahydronaphthalen-2-yl)boronic acid

To 6.60 g of 6-bromo-1,2,3,4-tetrahydronaphthalene in THF (60 ml) cooled on a dry ice-acetone bath, 25 ml of n-butyllithium (1.60 M/hexane solution) was added dropwise over 30 minutes in an argon stream, and after the dropwise addition, the reaction mixture was stirred for 1 hour under the same conditions. Then, 6.47 g of triisopropyl borate was added dropwise over 20 minutes, and after the dropwise addition, the reaction mixture was allowed to react for 3.5 hours. The reaction mixture was poured into ice-cold water and brought to almost neutral (pH 8) with ammonium chloride and then extracted with ethyl acetate (400 ml×1, 100 ml×2), and the organic layer was washed with saturated aqueous sodium chloride, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluent: methanol/chloroform=1/30), and the resulting solid was washed with a small amount of cold hexane to obtain 5.11 g of the desired product (yield 93%).

1. additionafter the dropwise addition
2. additionafter the dropwise addition
3. customto react for 3.5 hours
4. additionThe reaction mixture was poured into ice-cold water
5. extractionextracted with ethyl acetate (400 ml×1, 100 ml×2)
6. washthe organic layer was washed with saturated aqueous sodium chloride
7. dry with materialdried over anhydrous magnesium sulfate
8. concentrationconcentrated under reduced pressure
9. customThe resulting residue was purified by silica gel column chromatography (eluent: methanol/chloroform=1/30)
10. washthe resulting solid was washed with a small amount of cold hexane

ORD record

ord-a09cc59c0bd54de5a060a97511da7425

Source dataset

uspto-grants-2014_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08889732B2