| abstract |
A method for preparing a pyrazine compound represented by formula (I). 3-hydroxy-6-bromopyrazine-2-amide is used as a starting material, and under the condition of phosphorus oxychloride and DIEA, bromo-impurities are greatly reduced by adding inorganic chloride, so as to obtain 3,6-dichloropyrazine-2-carbonitrile having high purity. The obtained 3,6-dichloropyrazine-2-carbonitrile has high purity, is low in production costs, suitable for industrial amplification, and has great help for subsequent production of favipiravir API. |