Step 2. The method followed the synthesis of literature S5: 2,6-piperidinedimethanol (3.80 g, 26.21 mmol), iodoacetonitrile (5.24 g, 31.45 mmol), triethylamine (Et3N, 4.38 mL, 31.45 mmol) and anhydrous N,N-dimethylformamide (DMF, 20 mL) were added to the reaction system. Upon completion of the reaction, the product was purified by fast column chromatography using a solvent mixture of dichloromethane (CH2Cl2) and methanol (CH3OH) (9:1, v/v) as eluent to afford iodoacetonitrile as a straw-colored oily substance (2.5 g, 53% yield). the molecular ion peak m/z (M + H)+ was determined by FAB MS to be 185. iodoacetonitrile was prepared using the Finkelstein reaction: Bromoacetonitrile (BrCH2CN, 3.77 g, 0.0314 mmol) was added dropwise to an acetone solution of sodium iodide (NaI, 4.71 g, 0.031 mmol) under stirring. A precipitate of sodium bromide (NaBr) was produced within a few minutes of the reaction, indicating that a halogen exchange reaction had occurred. The sodium bromide was removed by filtration and the acetone was subsequently evaporated under vacuum to give the crude product iodoacetonitrile (5.24 g, 100% yield).
