Trifluoroacetic acid → (2S,3S)-3-methyl-2-[2-oxo-3-(4-quinolinylmethyl)-1-imidazolidinyl]pentanoic acid trifluoroacetat

Participants

Reaction Conditions

Reaction Steps

A solution containing the product from Example 3G (2.0 g, 8.69 mmol) in a mixture of benzene (40 mL) and ethanol (40 mL) was treated with 4-quinolinecarboxaldehyde (1.4 g, 8.91 mmol), heated at 70° C. for 2 hours, cooled to 25° C., treated with sodium borohydride (1.0 g, 26.75 mmol), stirred at 25° C. for 16 hours, quenched with sodium bicarbonate solution and partitioned between ethyl acetate and water. The organic phase was washed with brine, dried over MgSO4, filtered and concentrated. A solution of the residue (8.69 mmol) in 1,2-dichloroethane (300 mL) was treated with bis(4-nitrophenyl) carbonate (3.0 g, 9.86 mmol), heated at 70° C. for 16 hours, and partitioned between ethyl acetate and saturated NaHCO3. The organic phase was washed with brine, dried over MgSO4, filtered and concentrated. A solution of the residue (8.69 mmol) in dichloromethane (40 mL) was treated with trifluoracetic acid (40 mL), stirred at 25° C. for 1 hour and concentrated. The residue was chromatographed on silica gel eluting with 0-5% methanol in dichloromethane. A second purification using reversed phase chromatography on a C18 column, eluting with 5-100% acetonitrile in water (0.1% TFA) afforded the title compound (1.91 g, 48% yield).

Provenance & Evidence