2 Synthetic Procedures 1. The device was set up as drawn and cyclohexane (5 mL) was added from the upper end of the oil-water separator. Benzoic acid(8.0 g), 95% ethanol (18mL) cyclohexane(15mL)and concentrated sulfuric acid (3 mL) was refluxed until that there were almost no drops of water. The water was discharged and continue heating until most of the ethanol and cyclohexane are distilled into the oil-water separator 2. The resulting mixture was put into cold water. Sodium carbonate was added to adjust the ph to 7 3. The aqueous layer was extracted with ether (20mL) and combined with the product layer. The organic phase was dried over anhydrous magnesium sulfate for 0.5h 4. Evaporate the ether Then use an air bath to heat the temperature to 140 C Replace the straight condenser with an air condenser and collect the 210-213 C fractionSynthetic Procedures 1. The device was set up as drawn and cyclohexane (5 mL) was added from the upper end of the oil-water separator. Benzoic acid (8.0 g), 95% ethanol (18mL), cyclohexane (15mL) and concentrated sulfuric acid (3 mL) was refluxed until that there were almost no drops of water. The water was discharged and continue heating until most of the ethanol and cyclohexane are distilled into the oil-water separator. 2. The resulting mixture was put into cold water. Sodium carbonate was added to adjust the pH to 7. 3. The aqueous layer was extracted with ether (20mL) and combined with the product layer. The organic phase was dried over anhydrous magnesium sulfate for 0.5 h. 4. Evaporate the ether. Then use an air bath to heat the temperature to 140 ℃. Replace the straight condenser with an air condenser, and collect the 210-213 ℃ fraction