931-36-2

931-35-1

931-36-2

Dehydrogenation reaction: 550 g of 2-ethyl-4-methylimidazole dihydrochloride was placed in a three-necked flask fitted with an electric stirring device. Preparation of Ruanne nickel catalyst: 22 g of Ruanne nickel was added to 60 mL of 20 wt% potassium hydroxide aqueous solution and stirred for 15 min, followed by washing with pure water and ethanol. The prepared nickel ruanne catalyst was added to the reaction system. The reaction system was heated in an oil bath, the temperature was controlled to 190°C, and the reaction was continuously stirred for 3.5 hours. Upon completion of the reaction, the reaction solution was left to clarify, and the upper layer of clarified liquid was separated and removed. The residue was diluted with a small amount of toluene and filtered to remove the Nguyenay Ni catalyst. The filtrates were combined and vacuum distilled. Fractions with boiling points of 150-160°C/10 mmHg were collected to give 488 g of 2-ethyl-4-methylimidazole in 90.4% yield. The product was analyzed by gas chromatography and the purity was greater than 97%.