Imidazole → Guanethidine

Participants

Reaction Steps

First, 12 g (0.046 mol) of paradodecyl aniline was dissolved in 100 mL of THF and then put into a 100 mL three-neck round bottom flask. To this solution was added dropwise through a funnel over 10 minutes an acid remover prepared by mixing imidazole and triethyl amine at an equivalent mole ratio (0.023 mol). Then, to the resulting solution was slowly added dropwise through a dropping funnel over 20 minutes under a nitrogen atmosphere a solution prepared by dissolving 3.8 ml (0.047 mol) of acryloyl chloride in 20 mL of THF. At this time, the reaction mixture cooled with ice so as to keep its temperature below 5° C. Thereafter, the reaction proceeded at 0° C. for 6 hours, and then at 25° C. for 9 hours. After the completion of the reaction, the resulting solution was filtered with a filtering paper to remove salt precipitates, and then the solvent was eliminated by using an evaporator. The obtained solids were dissolved in 100 mL of dichloromethane and put into a separating funnel together with 50 mL of an aqueous solution of 10% NaHCO3 and shaken strongly to separate the aqueous solution layer and to remove the unreacted portion of acryloyl chloride. To the dichloromethane solution being separated was added 1.0 g of magnesium sulfate and the resulting mixture was stirred for 5 hours and filtered to remove a trace amount of water being dissolved in the solvent. The resulting dichloromethane solution was evaporated and then 100 mL of n-hexane was added thereto and stirred for 2 hours, and then was filtered to remove the unreacted portion of paradodecyl aniline remained in the solution. The solvent was removed from the resulting solution by using an evaporator to provide white solids of DOPAM (Yield: 95%). The chemical structure of DOPAM as synthesized was confirmed by a 1H nuclear magnetic resonance (1H-NMR) spectrum, and the results are the same as follows:

Provenance & Evidence