Trifluoroacetic anhydride → 1209459-79-9

5-Bromo-4-methoxy-2,3-dimethylpyridine 1-oxide (4.91 g) was dissolved in dichloromethane (60 ml), and trifluoroacetic anhydride (20 ml) was then added to the solution at room temperature. The resulting mixture was stirred overnight. Thereafter, the reaction solution was concentrated, and the concentrated solution was then dissolved in methanol (50 ml). The resulting mixture was stirred at 50° C. for 1 hour. The reaction solution was concentrated. The residue was dissolved in dichloromethane, and was then washed with a saturated sodium bicarbonate solution. The organic layer was dried over anhydrous sodium sulfate, and the filtrate was then concentrated. The residue was purified by silica gel column chromatography (hexane-ethyl acetate), so as to obtain the title compound (3.43 g) as a solid.

1. concentrationThereafter, the reaction solution was concentrated
2. dissolutionthe concentrated solution was then dissolved in methanol (50 ml)
3. stirringThe resulting mixture was stirred at 50° C. for 1 hour
4. concentrationThe reaction solution was concentrated
5. dissolutionThe residue was dissolved in dichloromethane
6. washwas then washed with a saturated sodium bicarbonate solution
7. dry with materialThe organic layer was dried over anhydrous sodium sulfate
8. concentrationthe filtrate was then concentrated
9. customThe residue was purified by silica gel column chromatography (hexane-ethyl acetate)

ORD record

ord-44ead2811d6942c997e6564a0261bda9

Source dataset

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08236813B2