1,3-Dimethyl-2-imidazolidinone → HCID 66589436, compound

Participants

Reaction Conditions

Reaction Steps

In a three-necked flask equipped with a dropping funnel and a reflux condenser were placed 19.4 g (170 millimoles) of 1,3-dimethyl-2-imidazolidinone and 50 mL of toluene in an atmosphere of nitrogen. Then, 13.0 g (85 millimoles) of phosphorus oxychloride was added and stirred at 65° C. Heating was stopped after 1 hour, the flask was cooled in an ice bath, and a solution containing the chlorination product of 1,3-dimethyl-2-imidazolidinone was obtained. To this solution were added 50 mL of dichloromethane and 23.6 mL (170 millimoles) of triethylamine in succession. To the resulting solution was added dropwise a solution of 13.8 mL (170 millimoles) of pyrrolidine in 50 mL of dichloromethane over a period of approximately 30 minutes while cooling the solution in an ice bath. Upon completion of the dropwise addition, the ice bath was removed and the solution was stirred at 55° C. The reaction mixture was cooled to room temperature after 1 hour, the insoluble matters were removed by filtration, and the filtrate was distilled off under reduced pressure. The residue was purified by column chromatography to give 15.9 g of 4,5-dihydro-1,3-dimethyl-2-(1-pyrrolidinyl)-1H-imidazolium chloride as a light yellow solid; this compound is a cyclic guanidine salt comprising the cation designated by chemical formula 1 and Cl− and is hereinafter referred to as cyclic guanidine salt 1. The solid showed a melting point of 49° C. and was hence a cyclic guanidine salt qualified for an ionic liquid.

Provenance & Evidence