Patent ID: 9346783
Filing Date: 2016-05-24
CPC Classification: A61P,C07D

Claim Text:
1. A method of producing an imidazole compound represented by the general formula (II′): or a salt thereof, wherein ring C′ represents a benzene ring optionally having substituent(s) or a monocyclic aromatic heterocyclic ring optionally having substituent(s); R the method comprising: oxidizing, in a reactor, an imidazole compound represented by the general formula (I′): or a salt thereof, wherein ring C′, R monitoring, by an oxidation reduction potential meter attached to the reactor, an electric potential of an oxidation reaction solution for producing the imidazole compound represented by the general formula (II′) by an oxidation reaction; detecting, by the oxidation reduction potential meter attached to the reactor, a predefined decrease of the electric potential of the oxidation reaction solution, wherein the decrease of the electric potential of the oxidation solution is measured from the point at which the electric potential of the oxidation reaction solution reaches its highest electric potential; and determining an end point for the oxidation reaction on the basis of detecting the predefined decrease of the electric potential, wherein the imidazole compound represented by the general formula (II′) or a salt thereof is lansoprazole or a salt thereof or an optically active substance thereof, wherein the predefined decrease of the electric potential is 70 mV.