Micafungin side chain also as known as 4-(5-(4-(pentyloxy)phenyl)isoxazol-3-yl)benzoic acid CAS number is 179162-55-1, his synthesis process is as following: 1. 23 g of p-hydroxyacetophenone, 28 g of bromopentane, 28 g of anhydrous potassium carbonate, dissolved in 115 mL of dimethylformamide (DMF), stirred at an internal temperature of 65 to 70℃, and stirred for 4 hours. The reaction liquid was a white suspension. After completion of the reaction, the mixture was cooled to room temperature, and then 210 mL of petroleum ether and 210 mL of water were successively added, and the mixture was shaken to leave a petroleum ether layer. The petroleum ether layer was washed successively with 120 ml of 0.5 mol/L sodium hydroxide solution and 120 ml of saturated brine, and the petroleum ether was dried over anhydrous magnesium sulfate for 30 min, and the magnesium sulfate was removed by filtration, and the petroleum ether was evaporated to give a colorless oily product. As a solid, the product…