Acetic Anhydride → N-(5-Bromo-4-(trifluoromethyl)pyridin-2-yl)acetamide

Temperatur

0 °C

A dry vessel under nitrogen at room temperature was charged with 5-bromo-4-(trifluoromethyl)pyridin-2-amine B1 (200 g, 830 mmol) and ethyl acetate (200 ml). The reaction mixture was cooled to 0° C. To the solution was added N,N-dimethylpyridin-4-amine (1.01 g, 8.29 mmol). Heptane (400 ml) was added and the mixture was cooled to 0° C. Acetic anhydride (109.6 ml, 1162 mmol) was added over a period of 60 min. The reaction mixture was warmed to 50° C. within 60 min. The reaction mixture was stirred at 50° C. for 18 h. Solvent (330 g) was removed by distillation (540-250 mbar, 50° C.) until a residue of ˜300 ml was obtained. The reaction mixture was allowed to cool to 20° C. Heptane (800 ml) was added and the mixture was stirred for 30 min. The precipitate was collected by filtration. The filter cake was washed with heptane (100 ml). The product was dried in a tray dryer for 16 h at 40° C., <20 mbar to yield 212 g (90%) B2 as sligthly brown solid.

1. temperaturethe mixture was cooled to 0° C
2. temperatureThe reaction mixture was warmed to 50° C. within 60 min
3. customSolvent (330 g) was removed by distillation (540-250 mbar, 50° C.) until a residue of ˜300 ml
4. customwas obtained
5. temperatureto cool to 20° C
6. stirringthe mixture was stirred for 30 min
7. filtrationThe precipitate was collected by filtration
8. washThe filter cake was washed with heptane (100 ml)
9. customThe product was dried in a tray dryer for 16 h at 40° C.

ORD-Eintrag

ord-affa86f66aeb496fb1db1a811dbaca99

Quelldatensatz

uspto-grants-2016_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09359326B2