Methanol → Methyl 2-Fluoro-5-nitrobenzoate

A solution of 2-fluoro-5-nitro-benzoic acid (3.702 g, 20 mmol) in anhydrous methanol (10.00 mL) was treated with 98% sulphuric acid and the solution was heated to reflux for 4 hours. The solvent was removed under vacuum and the residue was dissolved in ethyl acetate (50 mL). The solution was washed with saturated aqueous sodium bicarbonate (3×10 mL), brine until neutrality ant then water, and dried over anhydrous sodium sulphate. The solvent was removed under vacuum to afford a thick oil that started to crystallize. After adding n-hexane (3 mL) the crude was stored for 2 days in the fridge. The crystalline compound was filtered and washed with n-hexane to yield 3.147 g of the pure compound. By concentrating the mother liquors a second crop was obtained (390 mg) (y=89%).

1. temperaturethe solution was heated
2. temperatureto reflux for 4 hours
3. customThe solvent was removed under vacuum
4. dissolutionthe residue was dissolved in ethyl acetate (50 mL)
5. washThe solution was washed with saturated aqueous sodium bicarbonate (3×10 mL), brine until neutrality ant
6. dry with materialwater, and dried over anhydrous sodium sulphate
7. customThe solvent was removed under vacuum
8. customto afford a thick oil that
9. customto crystallize
10. additionAfter adding n-hexane (3 mL) the crude
11. filtrationThe crystalline compound was filtered
12. washwashed with n-hexane

ORD-Eintrag

ord-f7a23736fe814c46b82bbed9a9047509

Quelldatensatz

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08541429B2