Diisopropylethylamine → N'-{2-[5-(4-Bromo-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-N'-isopropyl-hydrazine-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

Triphosgene (1.05 g) was dissolved in DCM (17 mL) and stirred at 0° C. N′-Isopropyl-hydrazine-carboxylic acid methyl ester (1.00 g) and DIPEA (1.5 mL) were dissolved in DCM (25 mL), and mixture was added to triphosgene solution and stirred for 10 minutes. 5-(4-Bromo-phenyl)-2-pyrrolidin-2-yl-1H-imidazole (2.65 g) was added. Reaction was stirred at room temperature for 1 hour and extracted twice with water (10 mL), once with brine (10 mL), and evaporated under vacuum. The resulting oil was subjected to silica gel chromatography using a 40 g ISCO column and effluent of 0-100% ethyl acetate:hexanes. The fractions containing product were combined and the solvent was removed under vacuum, giving N′-{2-[5-(4-Bromo-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-N′-isopropyl-hydrazine-carboxylic acid methyl ester (533 mg, 16%).

Provenance & Evidence