3-broMo-4-ethylbenzoic acid

Bromine (7 ml, 0.14 mol) was added to a solution of 4-ethylbenzoic acid (15.0 g, 0.10 mol) in acetic acid (300 ml), nitric acid (65 ml) and water (50 ml). A solution of silver nitrate (17.0 g, 0.10 mmol) in water (50 ml) was added dropwise while vigorously stirring. The reaction mixture was stirred overnight at room temperature at which a yellow solid precipitated. The precipitate was collected by filtration, washed extensively with water and was extracted several times with CHCI3. The solution was washed with water and the solvent was removed under reduced pressure, yielding the 3- Bromo-4-ethy.benzoic acid (11.8 g, 52 percent yield) as a white solid. 1H NMR (300 MHz, CDCI3): 1.26 ppm (t, 3H, J = 7.8 Hz); 2.83 ppm (q, 2H, J = 7.8 Hz); 7.34 ppm (d, 1 H, J = 8.1 Hz); 7.97 ppm (dd, 1 H, J = 8.1 1.8 Hz); 8.27 ppm (d, 1 H, J = 1.8 Hz).Example 1.10. Synthesis of Function Ketone (Module C)30.2 g (0.2 mol) of p-methylaminobenzoic acid were mixed with 280 ml of dichloromethane at room temperature and stirred for 1 hour, Add 32.2 mL (0.4 mol) of pyridine, cool to -20°C, Bromine 10.76 mL (0.21 mol) was slowly added dropwise, The reaction was kept at low temperature for 5 hours, the reaction was quenched with 50 mL saturated aqueous solution of sodium thiosulfate, 100 mL of ethyl acetate was added, The organic phase was separated, washed with 300 mL of saturated aqueous sodium chloride, dried over anhydrous sodium sulfate and concentrated to about 100 mL under reduced pressure.Add 50 mL n-hexane, a solid precipitation, Stirred at room temperature for 2 hours, filtered with suction, Washed with 50 mL of dichloromethane, dried at 50 °C for 1 hour under vacuum to give 43.0 g as a white powdery solid, yield: 94percent.In the configuration of a thermometer, Add 18g of p-ethylbenzoic acid and 158g to the glass reactor of the stirring paddle and the condenserHydrobromic acid (20 wtpercent), after heating to 90 ° C, start to add hydrogen peroxide (30 wtpercent), The reaction was monitored using a chromatogram, and when the product yield was greater than 62percent, the reaction was stopped.The reaction was carried out for 49 h, at which time 40 g of hydrogen peroxide was consumed.The reaction concentration is only 8.3percent.The reaction solution was added to a Buchner funnel for filtration.After filtration, wash with 1000 ml of water.The obtained filter cake was vacuum dried at 80 ° C to a constant weight.Quantitative analysis by liquid chromatography, Obtaining 3, 5-dibromo-4-ethylbenzoic acid with a purity of 62percent, Another 35percent is 34.4 g (0.15 mol) of compound of formula 2 was mixed with 240 mL of tetrahydrofuran at room temperature and stirred for 1 hour and cooled to -20 ° C., Thionyl chloride 12.0 mL (0.165 mol) was added, About 0.5 mL of N, N-dimethylformamide was added dropwise, Continue to react for 4 hours, naturally rose to room temperature, 29.12 g (0.15 mol) of compound 3 and 24.1 mL (0.3 mol) of pyridine were added and the reaction was continued for 6 hours at room temperature.Add 300 mL of water end of the reaction, the organic layer was separated, Then 200 mL saturated aqueous sodium chloride solution, Dried over anhydrous sodium sulfate and concentrated under reduced pressure to a total volume of about 100 mL. 50 mL of n-hexane was added to precipitate a solid, Stirred at room temperature for 2.5 hours, filtered with suction, 50 °C vacuum dried for 1 hour, The white powdery solid 58.9 g, yield: 97percent.30.2 g (0.2 mol) of p-methylaminobenzoic acid were mixed with 280 ml of dichloromethane at room temperature and stirred for 1 hour, Add 32.2 mL (0.4 mol) of pyridine, cool to -20°C, Bromine 10.76 mL (0.21 mol) was slowly added dropwise, The reaction was kept at low temperature for 5 hours, the reaction was quenched with 50 mL saturated aqueous solution of sodium thiosulfate, 100 mL of ethyl acetate was added, The organic phase was separated, washed with 300 mL of saturated aqueous sodium chloride, dried over anhydrous sodium sulfate and concentrated to about 100 mL under reduced pressure.Add 50 mL n-hexane, a solid precipitation, Stirred at room temperature for 2 hours, filtered with suction, Washed with 50 mL of dichloromethane, dried at 50 °C for 1 hour under vacuum to give 43.0 g as a white powdery solid, yield: 94percent.

Molecular Weight:229.07
XLogP3:2.9
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:2
Exact Mass:227.97859
Monoisotopic Mass:227.97859
Topological Polar Surface Area:37.3
Heavy Atom Count:12
Complexity:170
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes