4-ethoxy-2,3-dimethyl-1-oxidopyridin-1-ium

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 22.9 g of 4-ethoxy-2,3-dimethylpyridine-1-oxide, 55.0 g (5.0 eq.) of acetic anhydride was added, and the mixture was allowed to react for 6 hours at 90 to 100° C. The acetic anhydride was distilled off, and the resulting concentrated residue was purified on a silica gel column, to obtain 28.2 g of 2-acetoxymethyl-3-methyl-4-ethoxy-pyridine as an oily matter. to react for 6 hours at 90 to 100° C The acetic anhydride was distilled off the resulting concentrated residue was purified on a silica gel column

Conditions: temp:30.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution prepared by diluting 8.6 g (2.0 eq.) of 60% sodium hydride with 200 mL of dimethylsulfoxide, 9.9 g (2.0 eq.) of anhydrous ethanol was added, and the mixture was allowed to react for one hour at 60° C. The reaction liquid was cooled to 30° C., and then a liquid containing 17.0 g of 4-chlor-2,3-dimethylpyridine-1-oxide dissolved in dimethylsulfoxide (70 mL) was added dropwise. The mixture was allowed to react for 2 hours at 40 to 50° C., and then was left to stand overnight at room temperature. 16 mL of water was added to the reaction liquid, and the mixture was concentrated, to obtain a residue in the form of a black paste. Subsequently, the residue was dissolved in 500 mL of water, and then the aqueous solution was extracted three times with 670 mL of chloroform. The extract was dried over anhydrous magnesium sulfate, and then was concentrated to dryness under reduced pressure. The obtained residue was purified on a silica gel column, to obtain 22.9 g of 4-ethoxy-2,3-dimethylpyridine-1-oxide. To a solution prepared was added to react for one hour at 60° C The reaction liquid was added dropwise to react for 2 hours at 40 to 50° C. was left the mixture was concentrated to obtain a residue in the form of a black paste the aqueous solution was extracted three times with 670 mL of chloroform The extract was dried over anhydrous magnesium sulfate was concentrated to dryness under reduced pressure The obtained residue was purified on a silica gel column