Synthesis and crystal structure of 6-fluoro-3-hydroxypyrazine-2-carboxamide.

As a RNA polymerase inhibitor, 6-fluoro-3-hydroxypyrazine-2-carboxamide commercially named favipiravir has been proved to have potent inhibitory activity against RNA viruses in vitro and in vivo. A four-step synthesis of the compound is described in this article, amidation, nitrification, reduction and fluorination with an overall yield of about 8%. In addition, we reported the crystal structure of the title compound. The molecule is almost planar and the intramolecular O-H(•••)O hydrogen bond makes a 6-member ring. In the crystal, molecules are packing governed by both hydrogen bonds and stacking interactions.