Sulfuric Acid → 5-Bromo-2-fluoro-1,3-dimethylbenzene

To a mixture of 4-Bromo-2,6-dimethylaniline (8.3 g, 42 mmol) at 5° C. and H2O (50 mL) was added conc H2SO4 (6.25 mL). NaNO2 (4.1 g) was added in portions until an excess was indicated by starch iodide paper. Water (30 mL) was added to make the mixture homogeneous. After transferring to a plastic container, HBF4 (50%, 13.7 g) was added dropwise with stirring. The resultant white precipitate was collected by vacuum filtration, washed with H2O (30 mL), MeOH (30 mL), and Et2O (60 mL), and dried over P2O5 under vacuum for 16 h. The solid was then heated in a glass flask with an open flame until all the solid had decomposed. The remaining liquid was diluted with Et2O (50 mL) and 0.5 M NaOH (30 mL). The organic layer was separated, washed with 0.5 M NaOH (25 mL), H2O (25 mL), brine (25 mL), dried (MgSO4), and concentrated in vacuo yielding 6.06 g (72%) of 1-bromo-4-fluoro-3,5-dimethylbenzene as a pale yellow liquid.

1. additionwas added dropwise
2. filtrationThe resultant white precipitate was collected by vacuum filtration
3. washwashed with H2O (30 mL), MeOH (30 mL), and Et2O (60 mL)
4. dry with materialdried over P2O5 under vacuum for 16 h
5. temperatureThe solid was then heated in a glass flask with
6. temperaturean open flame until all the solid
7. additionThe remaining liquid was diluted with Et2O (50 mL) and 0.5 M NaOH (30 mL)
8. customThe organic layer was separated
9. washwashed with 0.5 M NaOH (25 mL), H2O (25 mL), brine (25 mL)
10. dry with materialdried (MgSO4)
11. concentrationconcentrated in vacuo

ORD-Eintrag

ord-c23e18ac3014424a98269e671b0fb27e

Quelldatensatz

uspto-grants-2000_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06013652