Preparation method for high-purity ingavirin raw material

The invention discloses a preparation method for a high-purity ingavirin raw material. The preparation method comprises the following steps of: A. protecting amino group or imino group in histamine or histamine salt by adopting a nitrogen atom protecting method to obtain a compound in formula (II); B. refining the compound in formula (II) obtained from step A through using a recrystallization method; and C. removing nitrogen protecting group of the compound in formula (II) refined in step B to obtain a compound in formula (I). The preparation method is smart in conception, simple in flow, high in yield, the cost can be greatly lowered, and the high-purity histamine and pharmaceutically acceptable histamine salt can be prepared.