Hydrochloric Acid → methyl ((S)-1-((S)-2-(5-bromo-1H-imidazol-2-yl)pyrrolidin-1-yl)-3-methyl-1-oxobutan-2-yl)carbamate

Participants

Reaction Steps

A solution of (S)-tert-butyl 2-(5-bromo-1H-imidazol-2-yl)pyrrolidine-1-carboxylate (1.0 g, 3.2 mmol), 4M HCl solution in dioxanes (3.95 mL, 15.8 mmol) and methanol (4 mL) was stirred at room temperature for thirty minutes. The reaction was concentrated, suspended in dichloromethane, and thoroughly concentrated. This crude amine was dissolved in dimethylformamide (6.4 mL). To this solution were added (S)-2-(methoxycarbonylamino)-3-methylbutanoic acid (582 mg, 3.3 mmol), HATU (1.3 g, 3.3 mmol) and diisopropylethylamine (1.9 mL, 11.1 mmol). The reaction was stirred at room temperature for twenty minutes, and then diluted with ethyl acetate. The organic layer was washed with water and brine, dried (Na2SO4) and concentrated. The crude material was purified by flash column chromatography to yield methyl (S)-1-((S)-2-(5-bromo-1H-imidazol-2-yl)pyrrolidin-1-yl)-3-methyl-1-oxobutan-2-ylcarbamate (985 mg, 83%).

Provenance & Evidence