[CH3:1][C:2]1[C:7](Br)=[C:6]([CH3:9])[CH:5]=[CH:4][C:3]=1[O:10][CH3:11].C([Li])CCC.[B:17](OC)([O:20]C)[O:18]C.Cl>C1COCC1>[CH3:1][C:2]1[C:3]([O:10][CH3:11])=[CH:4][CH:5]=[C:6]([CH3:9])[C:7]=1[B:17]([OH:20])[OH:18]A solution of 2,4-dimethyl-3-bromoanisole (3.3 g, 15 mmol) in THF (15 mL) is added dropwise at −78° C. to a solution of n-butyllithium (11 mL of 1.6M in hexane, 17 mmol) in THF (35 mL). After 30 min, trimethyl borate (2.3 mL, 20 mmol) is added and the mixture is allowed to warm to room temperature overnight. The mixture is poured onto 10% HCl and extracted with EtOAc. The organic fraction is washed with saturated brine, dried (Na2SO4), and concentrated to give the desired product as a brownish oil. 1H NMR (CDCl3) 6.98 (d, 1H), 6.75 (d, 1H), 4.64 (br s), 3.80 (s, 3H), 2.27 (s, 3H), 2.22 (s, 3H).
Wird geladen…
