Sodium Hydroxide → 2-Butyl-4-dimethylaminomethylene-2-imidazolin-5-one

Participants

Reaction Steps

5.00 g (39.42 mmol) of glycine methyl ester hydrochloride was added in a single portion to a solution of 1.59 g (39.42 mmol) of sodium hydroxide in 13 ml of methanol at 0° C. The temperature dropped to -10° C. The mixture was then stirred for 15 minutes and during this time the temperature rose again to 0° C. 4.73 g (39.42 mmol) of methyl pentanimidate was added, and the mixture was stirred at room temperature for 3 hours. Then, during the course of 5 minutes, 5.62 g (43.39 mmol) of N,N-dimethylformamide dimethyl acetal was added, and the reaction mixture was stirred for a further 3 hours. Thereafter, solvent was removed on a Rotavapor, and the residue was treated with 40 ml of CH2Cl2 and 15 ml of water. After phase separation, the organic phase was washed with 10 ml of water, and then the combined H2O phases were washed twice, each time with 20 ml of CH2Cl2. Then, the combined organic phases were dried (MgSO4), filtered, concentrated on the Rotavapor and dried in a high vacuum. 6.70 g of 2-butyl-4-dimethylaminomethylene-2-imidazolin-5-one was obtained, having a content of about 90 percent, according to 1H-NMR. This corresponds to a yield of about 78 percent, based on the methyl pentanimidate.

Provenance & Evidence