申请人:MannKind Corporation
公开号:US20140243530A1
公开(公告)日:2014-08-28
Provided is a method for the synthesis of N-protected bis-3,6-[4-aminobutyl]-2,5-diketopiperazine including the step of heating a solution of ε-amino protected lysine in the presence of a catalyst selected from the group consisting of sulfuric acid, phosphoric acid, and phosphorus pentoxide.