Efficient production of 4-nitro-3,5-dimethylpyridine- <i>N</i> -oxide using microchannel technology

4-nitro-3,5-dimethylpyridine- N -oxide is a key intermediate in the preparation of esomeprazole, which involves oxidation followed by nitration reactions. However, the conventional batch reactor method necessitates use of excess peroxide, and nitric acid/sulfuric acid mixture which faces serious safety and environmental issues. Herein, we report efficient production of 4-nitro-3,5-dimethylpyridine- N -oxide using the microchannel technology which not only increases the yield but also significantly reduces safety risks and waste output.