PROCESS FOR THE PREPARATION OF 2-(2-PYRIDYLMETHYL)-SULFINYL-1H-BENZIMIDAZOLES

摘要

The present invention relates to an improved process for the preparation of substituted. 2-(2-pyridylmethyl)-sulfinyl-1H-benzimidazoles or its derivatives, which are useful for a medicament such as an inhibitor of gastric acid secretion or an anti-ulcer agent or an intermediate to produce medicaments in good yield and high purity. More particularly, the present invention relates to a process for preparing a sulfoxide compound of the formula (I) in good yield and relatively high purity and pharmaceutically acceptable salt, hydrate and solvate thereof. (I) wherein R₁ and R₃ are selected from the group consisting of hydrogen, methyl or C_1-4 alkoxy, R₂ is selected from the group consisting of substituted or unsubstituted C_1-4 alkoxy, R₄ is selected from the group consisting of hydrogen or substituted or unsubstituted C_1-4 alkoxy. Comprising the step of oxidizing a sulfide compound of formula (II) with Peroxyacetic acid or its derivatives necessarily at the pH 5-7 using aqueous sodium carbonate solution. (II) wherein R₁ R₂ R₃ & R₄ are as defined above.