The invention relates to the technical field of synthesis of 2-propylimidazole, in particular to a phase-transfer
catalysis oriented synthesis process of 2-propylimidazole, which comprises the following steps: pretreating a catalyst and an auxiliary agent, performing ultrasonic treatment on
tetrabutylammonium bromide, loading 18-crown-6,
roasting sodium carbonate, and microencapsulating
ascorbic acid, thereby obtaining the phase-transfer
catalysis oriented synthesis process of 2-propylimidazole. The
phase transfer catalyst is prepared by compounding treated
tetrabutylammonium bromide and loaded 18-crown-6, the assistant is prepared by compounding activated
sodium carbonate and
ascorbic acid microcapsules, adding the treated substance into a reaction kettle, adding an
organic solvent, stirring, sequentially adding the raw materials, cooling the reaction liquid, distilling to remove the
solvent, washing with water, separating liquid, carrying out
column chromatography gradient elution on the organic phase, and
drying, thereby obtaining the loaded 18-crown-6-
tetrabutylammonium bromide-supported 18-crown-6-tetrabutylammonium
bromide-supported 18-crown-6-tetrabutylammonium
bromide-supported 18-crown-6. And recrystallizing the product with
ethanol to obtain a high-purity product. According to the method, the catalyst and the auxiliary agent are pretreated, and pulse stirring and
gradient elution are combined, so that directional synthesis of 2-propylimidazole is realized. The product purity is not lower than 98%, the yield is not lower than 85%, side reactions and wastes are reduced, the cost is reduced, and the method is environment-friendly and efficient.