N-benzyl-2,6-difluoro-3,5-dimethoxyaniline → 2,6-Difluoro-3,5-dimethoxybenzenamine

N-Benzyl-2,6-difluoro-3,5-dimethoxyaniline (6.0 g, 21.5 mmol) was dissolved in THF (40 mL) and the solution hydrogenated over 20% palladium hydroxide on carbon catalyst (0.6 g) at 20° C.–25° C. 48–50 psi hydrogen pressure for 16 hours. The mixture was filtered, the catalyst washed with THF (2×15 mL) and the combined filtrates concentrated to a solid. This was recrystallized from heptane (10 mL) and toluene (4.5 mL). The mixture was cooled to −10° C. before filtering. The crystals were washed with heptane (2×10 ML) and vacuum dried at 35° C. to give 2,6-difluoro-3,5-dimethoxyaniline as off-white needles (3.85 g, 20.4 mmol). mp: 78° C.–79° C.

1. filtrationThe mixture was filtered
2. washthe catalyst washed with THF (2×15 mL)
3. concentrationthe combined filtrates concentrated to a solid
4. customThis was recrystallized from heptane (10 mL) and toluene (4.5 mL)
5. filtrationbefore filtering
6. washThe crystals were washed with heptane (2×10 ML) and vacuum
7. customdried at 35° C.

ORD-Eintrag

ord-43d6a613664e4a7a8ad29206dab72fc8

Quelldatensatz

uspto-grants-2007_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07196090B2