Dechloro-chlorocatechelin A (3), a deschloro-derivative of a microbial siderophore chlorocatechelin A (2), was synthesized from 2,3-dihydroxybenzoic acid, D-arginine, and 1-benzyl D-glutamate. The spectral data were unambiguously identical with those of mirubactin (1), revising its chemical structure. Mirubactin showed potent iron binding affinity, which was comparable to that of chlorocatechelin A (2).