2-{4-[3-(dimethylamino)propoxy]phenyl}-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

76579-64-1

61676-62-8

627899-90-5

GENERAL STEPS: To a 100 mL flame-dried two-neck flask was added 3-(4-bromophenoxy)-N,N-dimethyl-1-propanamine (3.0 g, 11.6 mmol) and freshly distilled tetrahydrofuran (80 mL). The resulting solution was cooled to -78 °C and n-butyllithium (8.7 mL, 13.9 mmol, 1.6 M hexane solution) was added dropwise over 10 min under nitrogen protection. The reaction mixture was stirred at -78 °C for 1 hour. Subsequently, isopropyl pinacol borate (2.6 g, 13.9 mmol) was quickly added and the resulting mixture was slowly warmed to room temperature for 24 hours. Upon completion of the reaction, the mixture was poured into 50 mL of water and extracted with chloroform (300 mL). The organic layers were combined, washed with saturated brine and dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporation and the residue was purified by silica gel column chromatography (eluent: ethyl acetate/dichloromethane) to afford the target product as a light yellow oil (1.6 g, yield: 45.0%). The product was characterized as follows: 1H NMR (400 MHz, CDCl3, Me4Si): δ = 7.77 (d, 2H, J = 8.8 Hz), 6.90 (d, 2H, J = 8.8 Hz), 3.94 (t, 2H, J = 6.4 Hz), 2.46 (t, 2H, J = 6.8 Hz), 2.26 (s, 6H), 1.88 (m , 2H, J = 6.8 Hz), 1.25 (s, 12H).13C NMR (100 MHz, CDCl3, Me4Si): 161.57, 136.73, 113.41, 83.13, 74.40, 66.02, 54.09, 45.42, 27.43, 25.00.Calculated elemental analysis values ( C17H28BNO3): C, 66.90; H, 9.25; N, 4.59. Measured values: C, 66.73; H, 9.23; N, 4.63. IR (KBr, cm-1): 2981, 2936, 2816, 2716, 1566, 1463, 1281, 1245.