Hydrochloric Acid → (S)-2-methoxycarbonylamino-3,3-diphenyl-propionic acid

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Reaction Conditions

Reaction Steps

was prepared as follows: A suspension of L-diphenylalanine (13.87 g, 57.5 mmol) in THF (100 mL), and saturated NaHCO3 (3 mL) being stirred at 0° C. was treated with neat methyl chloroformate (11.81 g, 125 mmol), stirred at 0° C. for 10 minutes and then at room temperature for 14 hours. 1 M HCl was then added and the mixture was extracted with DCM, dried over MgSO4, filtered and concentrated to give the title compound as a white solid, which was used without further purification. MS: m/z=322.1 (MNa+). Part B. The title compound was prepared as follows: To a mixture of N-(1-[4-(aminomethyl)thiophen-2-yl]-2-{[tert-butyl(dimethyl)silyl]oxy}ethyl)-N-(3-methylbutyl)benzenesulfonamide (87 mg, 0.227 mmol), N-(methoxycarbonyl)-β-phenyl-L-phenylalanine (75 mg, 0.250 mmol) and Hunig's base (131 μL, 0.751 mmol) in 2.3 mL DMF was added BOP reagent (111 mg, 0.25 mmol). The mixture was stirred at room temperature for 1 hour, and then quenched with saturated NaHCO3. The aqueous layer was extracted 2× with EtOAc, the EtOAc layers were combined and washed 3 times with water, once with brine and dried (MgSO4). The mixture was filtered, concentrated and purified on silica gel (EtOAc/hexanes). MS: m/z=686.2 (MNa+).

Provenance & Evidence