Hydrochloric Acid → methyl (2S,3R)-1-((S)-2-(5-(6-(4-(2-((S)-1-((R)-2-methoxycarbonylamino-2-phenylacetyl)pyrrolidin-2-yl)-1H-imidazol-5-yl)phenyl)naphthalen-2-yl)-1H-imidazol-2-yl)pyrrolidin-1-yl)-3-(difluoromethoxy)-1-oxobutan-2-ylcarbamate

Participants

Reaction Conditions

Reaction Steps

A solution of (S)-tert-butyl 2-(5-(4-(6-(2-((S)-1-((2S,3R)-3-(difluoromethoxy)-2-(methoxycarbonylamino)butanoyl)pyrrolidin-2-yl)-1H-imidazol-5-yl)naphthalen-2-yl)phenyl)-1H-imidazol-2-yl)pyrrolidine-1-carboxylate (68 mg, 0.09 mmol), dichloromethane (1 mL), 4M HCl in dioxane (0.07 mL, 0.28 mmol) and dimethylformamide (0.1 mL) was stirred at room temperature for one hour. Dichloromethane (5 mL) was added to the reaction and then concentrated to a solid. Dilution with dichloromethane and concentration was repeated a total of three times. The resulting solid was dissolved in methanol and filtered through a freebasing column (Stratospheres™ PL-HCO3MP SPE, Part #: PL3540-C603). The filtrate was concentrated and used without further purification. The crude material was dissolved in a 4:1 dichloromethane:dimethylformamide solution (0.8 mL). To this solution was added (R)-2-(methoxycarbonylamino)-2-phenylacetic acid (25 mg, 0.12 mmol) and COMU (41 mg, 0.1 mmol) and the reaction was cooled to 0° C. Diisopropylethylamine (0.045 mL, 0.24 mmol) was added and the reaction was stirred at 0° C. for one hour. The reaction was diluted with ethyl acetate and the organic layer was washed with water and brine, dried (MgSO4) and concentrated. The resulting residue was purified by preparative reverse phase HPLC (Gemini, 15 to 50% ACN/H2O+0.1% HCO2H) to yield methyl (2S,3R)-1-((S)-2-(5-(6-(4-(2-((S)-1-((R)-2-methoxycarbonylamino-2-phenylacetyl)pyrrolidin-2-yl)-1H-imidazol-5-yl)phenyl)naphthalen-2-yl)-1H-imidazol-2-yl)pyrrolidin-1-yl)-3-(difluoromethoxy)-1-oxobutan-2-ylcarbamate (34 mg, 45% over 2 steps). LCMS-ESI+: calculated for C47H48F2N8O7: 874.93; observed [M+1]+: 875.78.

Provenance & Evidence