Des-(3,4-Dihydrogen-3-oxo) Favipiravir is a building block related to Favipiravir(F103350). Favipiravir is used for the treatment of advanced Ebola virus infection in a small animal model. Favipiravir suppressed the replication of Zaire Ebola virus and prevented a lethal outcome in 100% of the animals. Based on the studies, Favipiravir can be a candidate for the treatment of Ebola hemorrhagic fever.