Hexane → 4-(Methylthio)phenylboronic acid

Temperature

0 °C

n-BuLi in hexane (2.5M, 625 mmol, 250 ml) is added slowly to a mechanically stirred solution of 4-bromothioanisole (100 g, 492 mmol) in THF (1 ) below −55° C. (internal temp.). After aging at −72° C. for 1 h trimethylborate (73 ml, 1.3 eq.) is added at such a rate to keep the internal temperature below −55° C. After 0.25 h at −78° C. the solution was allowed to warm to 0° C. for 10 min. 2N HCL (500 ml) is added and the solvent is evaporated. Water (500 ml) is added and the product is extracted with EtOAc (1.5 ). The organic layer is dried over Na2SO4, concentrated and the solid is stirred in hexane (500 ml) for 2 h. Filtartion gave 61.9 g (75%) of the desired product. 1H NMR (acetone-d6, 400 MHz) δ7.80 (d, 2H), 7.22 (d, 2H), 7.15 (s, 2H), 2.50 (s, 3H).

1. customthe internal temperature below −55° C
2. waitAfter 0.25 h at −78° C. the solution was allowed
3. addition2N HCL (500 ml) is added
4. customthe solvent is evaporated
5. additionWater (500 ml) is added
6. extractionthe product is extracted with EtOAc (1.5 )
7. dry with materialThe organic layer is dried over Na2SO4
8. concentrationconcentrated

ORD record

ord-c8506543b5e145caaa3e13cf5a6602b8

Source dataset

uspto-grants-2001_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06222048B1