Method for producing pyrrole compound

A method for producing a compound represented by the formula

• wherein R1 is an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group, R2 is a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, a chlorine atom or a fluorine atom, R3 is an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group, and R4 is an alkyl group, or a salt thereof, comprising
• (1) subjecting a compound represented by the formula
• wherein each symbol is as defined above, or a salt thereof to a reduction reaction, and then to hydrolysis to give a compound represented by the formula
• wherein each symbol is as defined above, or a salt thereof, wherein the reduction reaction is a continuous hydrogenation in a fixed bed reactor filled with a supported metal catalyst,
• (2) reacting the obtained compound with a compound represented by the formula
• R3—SO2—X (V)
• wherein R3 is as defined above, and X is a leaving group, or a salt thereof to give a compound represented by the formula
• wherein each symbol is as defined above, or a salt thereof, and
• (3) reacting the obtained compound with a compound represented by the formula
• R4—NH2 (VII)
• wherein R4 is as defined above, or a salt thereof.