Synthesis of Compound 2009: To a 2 L three-necked round-bottomed flask equipped with a temperature probe, magnetic stirring bar, nitrogen inlet, and constant-pressure dropping funnel was added (1S,2S)-1,2-diphenylethylenediamine (20 g, 0.094 mol) and dichloromethane (160 mL). The reaction mixture was cooled to 0-3 °C and 1 M sodium hydroxide solution (160 mL) was added slowly and dropwise while keeping the temperature below 5 °C. Subsequently, a solution of dichloromethane (320 mL) of p-toluenesulfonyl chloride (17.9 g, 0.094 mol) was added dropwise to the reaction system over a period of 2 hours. The biphasic reaction mixture was continued to be stirred at 0-5 °C for 1 h. Completion of the reaction was confirmed by thin layer chromatography (TLC, 50% ethyl acetate/heptane, UV detection). After completion of the reaction, the organic and aqueous phases were separated, and the organic phase was washed sequentially with water (2×320 mL) and saturated saline (320 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain the crude product. The crude product was dissolved in toluene (200 mL) at 70-80 °C, maintained at this temperature, and heptane (300 mL) was added in batches. The resulting slurry was cooled to 20-25 °C and stirred for 1 hour, then further cooled to 0-5 °C and stirred for 10 minutes. The solid was collected by filtration and washed with a heptane solution of 50% toluene (3 x 1 bed volume) to give compound 2009 (30.24 g, 88% yield) as a white powder.
