Hydrochloric Acid → HCID 59609876, compound

Participants

Reaction Steps

4-Butoxy-(2,3-difluorophenyl)cyclohexene (48) (11.0 g) and THF (200 ml) were put in a reaction vessel under a nitrogen atmosphere, and cooled to −74° C. sec-Butyllithium (1.00 M, in a n-hexane and cyclohexane solution; 50.0 ml) was added dropwise thereto in the temperature range of −74° C. to −70° C., and the mixture was stirred for another 2 hours. Subsequently, trimethyl borate (5.2 g) in a THF solution (50 ml) was added dropwise thereto in the temperature range of −74° C. to −65° C., and the mixture was stirred for 8 hours while allowing the temperature to come to 25° C. The reaction mixture obtained was added into a vessel containing an aqueous 1N—HCl solution (100 ml) and ice-water (500 ml), and mixed. Then, ethyl acetate (300 ml) was added thereto and the mixture was allowed to be separated into organic and aqueous phases, and an extractive operation was carried out. The organic phase obtained was fractionated, washed with water, a saturated aqueous solution of sodium hydrogencarbonate and brine and then dried over anhydrous magnesium sulfate. Then, the solvent was distilled off under reduced pressure, giving 10.7 g of 4-(4-butoxycyclohexenyl)-2,3-difluorophenyl boronic acid (49). The yield based on the compound (48) was 83.6%.

Provenance & Evidence