Method for manufacturing 3-(alkylsulfonyl)pyridine-2-carboxylic acid

A method for producing a compound represented by formula (8-N), comprising:

• a step of allowing a compound represented by formula (1-N):
• (wherein X represents a halogen atom)
• to react with a compound represented by formula (2):
• R2SM2 (2)
• (wherein R2 represents a C1-8 straight-chain alkyl group, and M2 represents a hydrogen atom or an alkali metal)
• to give a compound represented by formula (3-N):
• (wherein R2 and X are as defined above);
• a step of allowing the compound represented by formula (3-N) to react with hydrogen peroxide in the presence of a tungsten catalyst and an acid to give a compound represented by formula (6-N):
• (wherein R2 and X are as defined above);
• and
• a step of allowing the compound represented by formula (6-N) to react in the presence of a base and a heterogeneous transition metal catalyst to give a compound represented by formula (8-N):
• (wherein R2 is as defined above).

A method for producing a compound represented by formula (6-N), comprising:

• a step of allowing a compound represented by formula (1-N):
• (wherein X represents a halogen atom)
• to react with a compound represented by formula (2):
• R2SM2 (2)
• (wherein R2 represents a C1-8 straight-chain alkyl group, and M2 represents a hydrogen atom or an alkali metal)
• to give a compound represented by formula (3-N):
• (wherein R2 and X are as defined above);
• and
• a step of allowing the compound represented by formula (3-N) to react with hydrogen peroxide in the presence of a tungsten catalyst and an acid to give a compound represented by formula (6-N):
• (wherein R2 and X are as defined above).

A method for producing a compound represented by formula (3-N), comprising a step of allowing a compound represented by formula (1-N):

• (wherein X represents a halogen atom)
• to react with a compound represented by formula (2):
• R2SM2 (2)
• (wherein R2 represents a C1-8 straight-chain alkyl group, and M2 represents a hydrogen atom or an alkali metal) to give a compound represented by formula (3-N):
• (wherein R2 and X are as defined above).