Pleuromutilin derivatives with piperazine side chain, and preparation method and application thereof

The invention belongs to the field of pharmaceutical chemistry, and discloses pleuromutilin derivatives with piperazine side chain, and a preparation method and application thereof. The derivatives have the structure disclosed as Formula 2 or Formula 3, wherein R1 is hydrogen atom, methoxy, methyl, hydroxy, nitro or chlorine atom; R2 is hydrogen atom, methoxy, methyl, hydroxy, nitro or chlorine atom; R3 is hydrogen atom, methoxy, methyl, hydroxy, nitro or chlorine atom; and R4 is phenyl or methyl. The pleuromutilin derivatives with piperazine side chain have favorable in-vitro antimicrobial activity, have the advantage of lower preparation cost than valnemulin and retapamulin, and thus, are specially suitable to be used as a novel antibacterial drug for preventing and treating human or animal bacterial infective diseases.