Water → 4'-(2-Ethoxy-5-formyl-4-vinylimidazol-1-ylmethyl)-3'-fluorobiphenyl-2-carboxylic acid t-butyl ester

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Reaction Conditions

Reaction Steps

Intermediate (15a) (11.0 g, 21.8 mmol) was dissolved in 1,2-dimethoxyethane (100 mL, 1 mol). Tetrakis(triphenylphosphine)palladium(0) (252 mg, 218 μmol) was added and the mixture was stirred under nitrogen for 20 minutes. Water (48 mL, 2.6 mol), 2,4,6-trivinylcyclotriboroxane pyridine complex (2.1 g, 8.7 mmol) and potassium carbonate (3.0 g, 21.8 mmol) were then added and the mixture was heated at 90° C. under nitrogen. After 2 hours, the mixture was cooled to room temperature, diluted with EtOAc, washed with water and saturated aqueous NaCl, dried over MgSO4, filtered, and concentrated in vacuo. The mixture was purified by silica gel chromatography (0-50% EtOAc:hexanes) to yield intermediate (15b) (9.8 g). MS m/z: [M+H+] calcd for C26H27FN2O4, 451.2. found 451.0. 1H-NMR (CDCl3): 8.17 (1H, s), 7.79 (1H, d), 7.48 (1H, t), 7.40 (1H, t), 7.28 (1H, s), 7.01 (2H, m), 6.86 (1H, t), 6.67 (1H, m), 5.95 (1H, d), 5.41 (2H, s), 5.27 (1H, d), 4.48 (2H, q), 1.38 (3H, t), 1.25 (9H, s).

Provenance & Evidence