Imidazole → Guanethidine

Beteiligte Stoffe

Reaktionsschritte

Firstly, p-dodecylaniline (12 g, 0.046 mol) was dissolved in THF solvent (100 mL). The solution was poured into a 100 mL three-mouthed round flask, and an acid eliminator was added dropwise through a funnel for 10 minutes, where the acid eliminator contained imidazole and triethyl amine at the same mole fraction (0.023 mol). Under the nitrogen atmosphere, a solution containing acryloyl chloride (3.8 mL, 0.047 mol) in THF (20 mL) was gradually added dropwise to the mixed solution through a dropping funnel for 20 minutes. Meanwhile, the solution was cooled on ice bath to prevent the temperature of the reaction mixture from rising above 5° C. After 6 hours of reaction at 0° C., the solution was kept at 25° C. for more 9 hours of reaction. Upon completion of the reaction, the solution was passed through a filter paper to eliminate precipitated salts, and the solvent was evaporated from the filtrate on an evaporator. The solid thus obtained was dissolved in dichloromethane (100 mL) and added to a separatory funnel along with 10% aqueous NaHCO3 solution (50 mL). The funnel was shaken vigorously and set aside to allow for the complete separation of the aqueous phase and thereby to remove unreacted acryloyl chloride. Magnesium sulfate (1.0 g) was added to the separated dichloromethane solution. After stirred for 5 hours, the solution was subjected to filtration to remove a trace amount of water dissolved in the solvent. The dichloromethane solution thus obtained was kept on the evaporator, and n-hexane (100 mL) was added. The solution was stirred for 2 hours, and unreacted p-dodecyl aniline was filtered out from the solution. The filtrate was then removed of the solvent on the evaporator to yield a white solid DOPAM product (yield 95%). The chemical structure of the DOPAM product was identified by hydrogen nuclear magnetic resonance (1H-NMR) spectrum. The results were as follows.

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