Hydrochloric Acid → 1-Cyclopentyl-3-methyl-2-oxo-4-imidazolidinecarboxylic acid

Participants

Reaction Steps

A stirred solution of methyl 3-methyl-2-oxo-4-imidazolidinecarboxylate (316 mg, 2.0 mmol) (prepared as described in step (ii) of Example 8) in N,N-dimethylformamide (5 ml) was cooled to 0° C. under argon and treated with sodium hydride (60% dispersion in oil) (80 mg, 2.0 mmol). After 10 minutes bromocyclopentane (298 mg, 2.0 mmol) was added and the reaction mixture was stirred at room temperature for 3 hours and then at 60° C. for 18 hours. After cooling to room temperature additional sodium hydride (60% dispersion in oil) (80 mg, 2.0 mmol) was added followed by bromocyclopentane (298 mg, 2.0 mmol) and the reaction mixture was heated at 60° C. for 48 hours. After cooling to room temperature a solution of lithium hydroxide (0.057 g, 2.400 mmol) in water (1 ml) was added and the reaction mixture was stirred at room temperature for 30 minutes. Hydrochloric acid (2M) was added to adjust the pH of the mixture to pH 2 and the solvent was evaporated. Dimethylsulfoxide (3 ml) was added to the residue and the suspension was filtered. The filtrate was purified by mass-directed automated HPLC to give 1-cyclopentyl-3-methyl-2-oxo-4-imidazolidinecarboxylic acid (39 mg, 9%). LC/MS [M+H]+=213. Mass-Directed Automated HPLC

Provenance & Evidence