122547-49-3

106559-80-2

122547-49-3

At room temperature, 150 g of Intermediate II was mixed with 1110 mL of dichloromethane and stirred until completely dissolved, followed by the addition of 18 g of triphenylphosphine and an ethyl acetate solution of sodium caprylate (prepared from 92 g of sodium isooctanoate and 1110 mL of ethyl acetate) to give a pale yellow transparent liquid. After displacing the air in the reaction system with nitrogen for 5 minutes, 2.664 g of tetrakis(triphenylphosphine)palladium was added under nitrogen protection. After addition, the reaction temperature was maintained at 25~30°C and stirred continuously under nitrogen protection for 40 minutes. Upon completion of the reaction, 40 g of pure water was added to the reaction solution at room temperature, and crystallization was carried out at a controlled temperature of 20~30 °C for 2 h. The reaction was then cooled to -5~0 °C and stirring was continued for 2 h. The reaction mixture was separated by filtration. The reaction mixture was separated by filtration and the filter cake was washed with 200 mL x 3 of ethyl acetate. Finally, the filter cake was dried under vacuum at 35~40 °C to give 119 g of white powdery product in 73.3% molar yield.