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

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Reaction Conditions

Reaction Steps

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).

Provenance & Evidence