Trifluoroacetic acid → 2,6-Dichloropyridine N-Oxide

Temperature

95 °C

A mixture of 2,6-dichloropyridine (2 g, 13.6 mmol) in TFA (6 mL) and 30% H2O2 (2.5 mL) was prepared at 0° C., after which the mixture was heated to reflux at 90-100° C. After 7 hour at this temperature, the mixture was cooled to room temperature and neutralized with IN NaOH solution to pH 8-9. The aqueous layer was extracted with petroleum ether (200 mL×3) and the organic layer was dried over sodium sulfate, filtered, and concentrated to dryness under vacuum. The residue was purified by column chromatography over 100-200 mesh silica gel, eluting with 20:80 acetone: hexanes, to afford the pure compound as a colorless solid (1.75 g, yield 80%).

1. customwas prepared at 0° C.
2. temperatureafter which the mixture was heated
3. extractionThe aqueous layer was extracted with petroleum ether (200 mL×3)
4. dry with materialthe organic layer was dried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated to dryness under vacuum
7. customThe residue was purified by column chromatography over 100-200 mesh silica gel
8. washeluting with 20:80 acetone

ORD record

ord-ba48d286271046bc99ec50e25a763a61

Source dataset

uspto-grants-2009_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07622486B2