4-ethyl-1-oxidopyridin-1-ium

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

Procedure: A solution of 4-ethylpyridine (10.7 g, 0.10 mol) in 35 ml of acetic acid heated at 95-100° C. is treated dropwise over a 18 min period with 30% hydrogen peroxide (28 ml). After 4 h, the excess hydrogen peroxide is decomposed by the portionwise addition of paraformaldehyde (10.0 g) at the previously maintained temperature until a negative starch iodide test is obtained. The reaction mixture is cooled and concentrated at reduced pressure. The residue is chromatographed with 325 g of silica gel packed and eluted initially with acetone-chloroform-methanol (3:6.7:0.3) and thereafter with an increasing methanol gradient to obtain 10.55 g (83%) of 4-Ethylpyridine-1-oxide. is obtained The reaction mixture is cooled concentrated at reduced pressure The residue is chromatographed with 325 g of silica gel eluted initially with acetone-chloroform-methanol (3:6.7:0.3)