需求描述：Synthesis of 11-Mercaptoundecylphosphorylcholine. The reaction route for the synthesis of 11-mercaptoundecylphosphorylcholine (PC thiol) is presented in Scheme 1. A methanol solution (30 mL) containing 11-mercapto-1-undecanol (2.05 g) (1) was titrated by 1 M iodine methanol solution until the solution turned light yellow, and then the reaction was quenched with sodium bisulfite. 11-Hydroxyundecyl disulfide (2) was precipitated from the methanol solution at 0 C and recrystallized from ethanol with a yield of 1.85 g (90%). 2 (0.407 g, 1 mmol) and triethylamine (0.35 mL, 2.5 mmol) were dissolved in 15 mL of chloroform (CHCl3). This solution was slowly added into 2-chloro-1,3,2,-dioxaphospholane-2-oxide (0.21 mL, ∼2.4 mmol) anhydrous THF (40 mL) solution at -18 C. The mixture was allowed to warm to ambient temperature over 2 h. The reaction mixture was then cooled to 0 C and filtered. The filtrate was concentrated in vacuo at room temperature without further purification, and the product (3) is a colorless to light-yellow oil. 3 and trimethylamine (0.5 mL, 5.5 mol) in anhydrous methane chloride (35 mL) at -15 C were sealed in a bomb, which was heated to 55 C and stirred for 24 h. The reaction mixture was cooled and filtered to give a white solid powder (4, 0.4 g). The white solid powder (0.4 g) was dissolved in ethanol (3 mL), and 1,4-dithio-D,L-threitol (DTT, 0.4 g) was added. The pH of the solution was adjusted to 9 with concentrated NH3‚H2O. The solution was stirred for h