4-(Ethoxycarbonyl)phenylboronic acid

white to off-white powder

Preparation of 4-(ethoxycarbonyl)benzeneboronic acid. In a 20L reactor, 8.0 Kg of absolute ethanol was added p-carboxyphenyl boronic acid and 1.66 Kg (10 mol), stirring the reactor was heated to 50 , temperature 50 ~ 65 thionyl chloride was added dropwise to the kettle (1.55 Kg, 13 mol), dropwise after the reaction warmed to reflux for 2-3 hours.After completion of the reaction was confirmed (TLC: n-heptane: ethyl acetate = 2: 1), the reaction solution was cooled, the solvent evaporated under reduced pressure, after adding heptane, cooled -10 ~ 0 , stirred for 1 hour was filtered, minus 100 The solid was dried pressure until no impurities confirmation HNMR (HNMR: DMSO-dTo the condenser with a tube, Dried 1L dry eggplant-shaped bottle in turn by adding 3A molecular sieve dried anhydrous ethanol 400mL, (0.2mol) of 4-carboxyphenylboronic acid, 8mL of concentrated sulfuric acid, and refluxed at 105 ~ 110 for 24 hours. TLC (CHCl3 / MeOH = 10/1)Ethanol was evaporated under reduced pressure to give a white solid, 500 mL of water was added, Saturated NaHCO3 solution 250mL washing, washing to neutral, dry, To obtain 33.5 g of 4-ethoxycarbonylphenylboronic acid (yield: 86.3percent).In 500mL three-necked flask, Ethyl 4-iodobenzoate (20.9 g, 75.8 mmol) was dissolved in dry THF (300.0 mL)Triisopropyl borate (42.8 g, 227.4 mmol) was added, The temperature was lowered to -78 ° C and n-butyllithium (9.7 g, 151.6 mmol) was added dropwise.Maintain the reaction temperature 0.5h.The reaction was completed, quenched with saturated aqueous ammonium chloride solution, 1mol / L hydrochloric acid to adjust the pH to 1, Ethyl acetate (150.0 mL × 3), the organic phases were combined, Saturated brine (100 mL × 1), dried over anhydrous sodium sulfate, The solvent was distilled off under reduced pressure, the residue was beaten with n-hexane, The filtrate was filtered to give 4-ethoxycarbonyl phenylboronic acid 13.5g, a yield of 92.0percent.In 500mL three-necked flask, Ethyl 4-iodobenzoate (21.1 g, 76.4 mmol) was dissolved in dry THF (200.0 mL)Tri-n-butyl borate (26.4 g, 114.5 mmol) was added, The temperature was lowered to -78 ° C and n-butyllithium (6.9 g, 106.9 mmol) was added dropwise.Maintain the reaction temperature 1h.The reaction was completed, quenched with saturated aqueous ammonium chloride solution, 1mol / L hydrochloric acid to adjust the pH to 1, Ethyl acetate (100.0 mL × 3), the organic phases were combined, Saturated brine (60 mL × 1), dried over anhydrous sodium sulfate, The solvent was distilled off under reduced pressure, the residue was beaten with n-hexane, The filtrate was filtered with 4-ethoxycarbonyl phenylboronic acid 14.0g, Yield 94.4percent.General procedure: To a solution of arylamine (0.5 mmol, 1.0 equiv) in MeOH(1.0 mL) was added HCl (0.5 mL, 1.5 mmol, 3.0 equiv), followed by H2O (0.5 ml). This mixture was stirred 2 min, and the NaNO2 solution (0.25 mL) was then added. The NaNO2 solution was prepared by dissolving 35 mg ofNaNO2 in H2O (0.25 mL). This mixture was stirred 30 minat 0–5 °C, followed by HCl (135 mg, 1.5 mmol, 3.0 equivalents) in MeOH (1.0 mL). This mixture was stirred 60min. H2O (10 mL) was added to reaction mixture, then extracted with CH2Cl2 (50 mL, 3×). The combined organic layer was dried over Na2SO4, followed by evaporation to give the products.

suzuki reaction

Molecular Weight:193.99
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:4
Exact Mass:194.0750390
Monoisotopic Mass:194.0750390
Topological Polar Surface Area:66.8
Heavy Atom Count:14
Complexity:187
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes