Cesium carbonate → HCID 57413864, compound

Participants

Reaction Conditions

Reaction Steps

Under nitrogen atmosphere, the mixture of [(2R,3S,4S,5R,6R)-4,5-diacetoxy-6-(acetoxymethyl)-2-(4-bromo-2-methyl-phenoxy)tetrahydropyran-3-yl]acetate (0.517 g, 1 mmol), 3-(N-methylaminocarbonyl)phenylboronic acid pinacol ester (0.392 g, 1.5 mmol), cesium carbonate (0.977 g, 3 mmol) and tetrakis(triphenylphosphine)palladium (0.116 g, 0.1 mmol) in dioxane/water (15 mL/3 mL) was heated at 80° C. with stirring for 1 h under a nitrogen atmosphere. After cooling to RT, the mixture was filtered through silica gel column to remove the metal catalyst and salts with hexane/ethyl acetate combinations as eluent. The filtrate was concentrated, and then dried in vacuo. The residue was diluted with 15 mL of methanol containing a catalytic amount of sodium methoxide (0.02 M) and the mixture was stirred at RT overnight. H+ exchange resin (DOWEX 50WX4-100) was added to neutralize the mixture. The resin was filtered off and the filtrate was concentrated. The resulting residue was purified by silica gel chromatography with CH2Cl2/MeOH combinations as eluent, giving the title compound (0.260 g) in 64% yield for two steps. 1H NMR (300 MHz, METHANOL-d4) δ ppm 7.94 (t, J=1.65 Hz, 1H), 7.57-7.72 (m, 2H), 7.33-7.50 (m, 3H), 7.23 (d, J=8.52 Hz, 1H), 5.48 (d, J=1.92 Hz, 1H), 4.00 (dd, J=1.79, 3.43 Hz, 1H), 3.83-3.94 (m, 1H), 3.60-3.76 (m, 3H), 3.46-3.58 (m, 1H), 2.87 (s, 3H), 2.24 (s, 3H). MS (ESI): found: [M+H]+, 404.2.

Provenance & Evidence