Synthesis
The general procedure for the synthesis of 2-chlorophenylethanol from o-chlorophenylacetic acid was as follows: first, 20 g of o-chlorophenylacetic acid (o-S1) was dissolved in 200 ml of tetrahydrofuran, stirred and cooled to 0 °C. Subsequently, 8.9 g of lithium aluminum hydride was added in batches and Bi was added as a catalyst. The reaction mixture was warmed up to 25?30°C for the reaction. Upon completion of the reaction, the reaction was terminated by adding 300 ml of water and extracted with 400 ml of dichloromethane. After separation of the organic phase, 20 g of anhydrous sodium sulfate was added for drying. Concentration under reduced pressure at 30-35°C gave 18.3 g of light yellow oil (o-S1-1). Next, phosphorus tribromide was slowly added dropwise to the reaction vial containing o-S1-1 under ice bath conditions, controlling the dropwise temperature at 0-10 °C. After the dropwise addition, stirring was continued for 10 min until white smoke was generated. Subsequently, the reaction mixture was warmed up to 75~80°C and held at this temperature with stirring for 2 hours. Upon completion of the reaction, 30 ml of saturated sodium bicarbonate solution was added to neutralize the reaction and extracted with 200 ml of ethyl acetate. After separation of the organic phase, 20 g of anhydrous sodium sulfate was added for drying. Finally, it was concentrated under reduced pressure at 40?45 °C to give 22.4 g of yellow liquid (neighboring S2) in 87.0% yield.
References
[1] Journal of Medicinal Chemistry, 1981, vol. 24, # 6, p. 678 - 683
[2] Patent: US6342501, 2002, B1. Location in patent: Scheme 2
[3] Angewandte Chemie - International Edition, 2015, vol. 54, # 36, p. 10596 - 10599
[4] Angew. Chem., 2015, vol. 127, p. 10742 - 10745,4
[5] Journal of Organic Chemistry, 1964, vol. 29, p. 3175 - 3179
