Trifluoroacetic acid → HCID 86679679, compound

To a 0° C. solution of 3-methoxy-1H-pyrrole-2,5-dione ({see M. Couturier, J. L. Tucker, B. M. Andresen, P. Dube, J. T. Negri, Org. Lett., 2001, 3, 465-467}, 950 mg, 7.47 mmol) and TFA (0.070 mL, 0.897 mmol) in DCM (70 mL) was added slowly a solution of N-benzyl-1-methoxy-N-[(trimethylsilyl)methyl]methanamine (3.06 mL, 12.0 mmol) in DCM (30 mL) at a rate such to maintain the internal reaction temperature <2° C. The resulting bright yellow solution was slowly warmed to ambient temperature and stirred for 18 hrs. The reaction mixture was then cooled to 0° C. and a solution of N-benzyl-1-methoxy-N-[(trimethylsilyl)methyl]methanamine (0.956 mL, 3.74 mmol) in DCM (1 mL) was added dropwise and was warmed to rt and stirred for 3 hrs. The reaction mixture was diluted with saturated sodium bicarbonate (25 mL), the layers were separated and the organic solution was dried (magnesium sulfate), filtered and concentrated under reduced pressure, giving a thick, yellow oil. The crude residue was purified by column chromatography eluting with 5%-50% EtOAc/heptane and again with 0%-25% EtOAc/Heptane to afford the titled compound (1.19 g, 61% yield, 70% purity) as a clear oil that was carried forward to the next step without further purification.

1. temperatureto maintain the internal reaction temperature <2° C
2. temperatureThe reaction mixture was then cooled to 0° C.
3. temperaturewas warmed to rt
4. stirringstirred for 3 hrs
5. customthe layers were separated
6. dry with materialthe organic solution was dried (magnesium sulfate)
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customgiving a thick, yellow oil
10. customThe crude residue was purified by column chromatography
11. washeluting with 5%-50% EtOAc/heptane and again with 0%-25% EtOAc/Heptane

ORD record

ord-4163b528ff05475aa337d88d20def677

Source dataset

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09040547B2