2,3-Difluoro-4-methoxybenzeneboronic acid → 4-(((2',3'-Difluoro-4'-methoxy-5-(trifluoromethyl)biphenyl-3-yl)methoxy)methyl)-4-phenylpiperidine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

tert-Butyl 4-((3-bromo-5-(trifluoromethyl)benzyloxy)methyl)-4-phenylpiperidine-1-carboxylate (150 mg, 0.28 mmol), 2,3-difluoro-4-methoxyphenylboronic acid (139 mg, 0.84 mmol), and tetrakis(triphenylphosphine) palladium(0) (33 mg, 0.03 mmol) were combined in dry tetrahydrofuran (3 mL) in a microwave tube and sealed. After flushing with nitrogen, 1.0 mL of a 1 N potassium hydroxide aqueous solution was introduced. The mixture was heated at 120° C. for 1 h via microwave. After cooling to room temperature, the reaction mixture was concentrated and treated with a trifluoroacetic acid/methylene chloride mixture (1:1, 2 mL) for 1 h. The solvent was removed in vacuo and the resulting crude mixture passed through a strong cation exchange column. After washing the column with several volumes of methanol, the product was eluted by washing the column with 2 M ammonia in methanol and concentrated to afford 45 mg (33%). 1H-NMR (CDCl3, 500 MHz) δ 7.57 (s, 1H), 7.26-7.38 (m, 6H), 7.13-7.17 (m, 1H), 7.00-7.06 (m, 1H), 6.77-6.83 (m, 1H), 4.41 (s, 2H), 3.93 (s, 3H), 3.44 (s, 2H), 2.84-2.92 (m, 2H), 2.68-2.77 (m, 2H), 2.13-2.18 (m, 2H), 1.83-1.92 (m, 2H). Mass spec.: 492.01 (MH)+. Accurate mass spec.: m/z 492.1978 [MH]+, Δ=3.3 ppm.

Herkunft & Nachweise