Trifluoroacetic acid → (3R,10S)-2-methyl-5-methyl-3-(9-oxo-1,8-diazatricyclo[10.6.1.013,18]nonadeca-12(19),13(18),14,16-tetraen-10-ylcarbamoyl)hexanoic acid

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Reaction Steps

Alternatively, the less polar stereoisomer of (3R,10S)-2-methyl-5-methyl-3-(9-oxo-1,8-diazatricyclo-[10.6.1.013,18 ]nonadeca-12(19),13(18),14,16-tetraen-10-ylcarbamoyl)hexanoic acid t-butyl ester prepared in Example 5D above (15 mg) was taken up in CH2 Cl2 (2.4 mL) and TFA (0.6 mL) and the resulting mixture was stirred at room temperature for 4 hrs. The solvent was removed under reduced pressure at 35° C. Then ethyl acetate was added and the solution was washed with water (3×10 mL). The organic layer was dried over Na2SO4, filtered and evaporated to dryness. Recrystallization from ethyl acetate/petroleum ether gave (3R,10S)-2-methyl-5-methyl-3-(9-oxo-1,8-diazatricyclo[10.6.1.013,18 ]nonadeca-12(19),13(18),14,16-tetraen-10-ylcarbamoyl)hexanoic acid as a white solid (7 mg), MS: 456.3 (M+H)+.

Provenance & Evidence