Acetonitrile → methyl 6-chloronicotinate N-oxide

Temperature

0 °C

To a 500 mL round bottom flask containing methyl 6-chloronicotinate (4.50 g, 26.2 mmol) was added MeCN (100 mL). The resulting mixture was then stirred at 0° C. for 10 min. At this time, urea hydrogen peroxide (4.93 g, 52.5 mmol) solid was added before the dropwise addition of trifluoroacetic anhydride (7.41 mL, 52.5 mmol). The reaction was stirred for 30 min and then the ice bath was removed. The reaction was then stirred for 3 h and then the bulk of MeCN was removed by rotary evaporation. The residue was dissolved in EtOAc (150 mL) and washed with sodium thiosulfate (aqueous, 0.5 M, 2×100 mL), water (100 mL), brine (100 mL), dried with sodium sulfate and concentrated to a tan solid. The solid thus obtained was dissolved in DCM (150 mL) and MeOH (30 mL). The solid residue was removed by filtration, and the filtrate was concentrated affording 2-chloro-5-(methoxycarbonyl)pyridine 1-oxide as a tan solid.

1. stirringThe reaction was stirred for 30 min
2. customthe ice bath was removed
3. stirringThe reaction was then stirred for 3 h
4. customthe bulk of MeCN was removed by rotary evaporation
5. dissolutionThe residue was dissolved in EtOAc (150 mL)
6. washwashed with sodium thiosulfate (aqueous, 0.5 M, 2×100 mL), water (100 mL), brine (100 mL)
7. dry with materialdried with sodium sulfate
8. concentrationconcentrated to a tan solid
9. customThe solid thus obtained
10. customThe solid residue was removed by filtration
11. concentrationthe filtrate was concentrated

ORD record

ord-3f7c1e2a2b8d49f09fa0465e51b14230

Source dataset

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09096527B2