Patent ID: 8703959

Claim:
A method for producing a substituted amino-6-methylpyridine-N-oxide derivative represented by formula (1-a) comprising oxidizing a substituted amino-6-methylpyridine derivative represented by formula (2) using a peroxide in a presence of a tungstophosphoric acid salt represented by formula (3): wherein A represents a hydroxyl group, a thiol group, an amino group, a nitro group, a halogen atom or an organic group, k represents any one of integers of 0 to 3, R 3 represents a hydrogen atom, an unsubstituted or substituted alkylcarbonyl group, an unsubstituted or substituted arylcarbonyl group, or an unsubstituted or substituted alkoxycarbonyl group, R 4 represents an unsubstituted or substituted alkylcarbonyl group, an unsubstituted or substituted arylcarbonyl group, an unsubstituted or substituted heteroarylcarbonyl group, an unsubstituted or substituted alkoxycarbonyl group, an unsubstituted or substituted alkylsulfonyl group, or an unsubstituted or substituted arylsulfonyl group, m represents any one of integers of 1 to 4, wherein k+m≦4, and Q represents a quaternary nitrogen cation.