Hydrochloric Acid → 4-Chloro-2,3,5-trimethyl-1-oxidopyridin-1-ium

Temperatur

70 °C

To 2,3,5-trimethyl-4-nitropyridine1-oxide (850 g, 4.67 mol), water (400 g) and 36% concentrated hydrochloric acid (1.69 kg) was added and the mixture was heated to 70° C. To the mixture, N,N-dimethylformamide (115 mL) was added and then the resultant mixture was heated to 100° C. After completion of the reaction, the reaction mixture was cooled to 20° C. and poured into a mixture of potassium carbonate (1.40 kg) and water (7 L). The mixture was extracted with chloroform (1.0 L×3), the organic layer dried over sodium sulfate and concentrated. The obtained crude product was stirred for 2 hours in a mixture of diisopropyl ether (500 mL) and n-hexane (1.0 L), and thereafter, sucking filtration was performed. The obtained wet product was dried under vacuum overnight to obtain a desired product (666.4 g).

1. customAfter completion of the reaction
2. temperaturethe reaction mixture was cooled to 20° C.
3. extractionThe mixture was extracted with chloroform (1.0 L×3)
4. dry with materialthe organic layer dried over sodium sulfate
5. concentrationconcentrated
6. customThe obtained crude product
7. filtrationfiltration
8. customThe obtained wet product was dried under vacuum overnight

ORD-Eintrag

ord-fc7aa3e18e564e2f9ac740f48e7e47e0

Quelldatensatz

uspto-grants-2008_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07425634B2