A series of highly porous University of Michigan Crystalline Material (UMCM-1) type Zn-based metal–organic frameworks (MOFs) were synthesized from mono- and bi-functionalized benzenedicarboxylate (BDC) ligands. In total, 16 new functionalized UMCM-1 derivatives were obtained by a combination of pre- and postsynthetic functionalization. Through postsynthetic modification (PSM), amino–halo bifunctional MOFs were converted into amide–halo materials via solid-state acylation reactions. A series of bifunctional MOFs containing Cl, Br, and I groups revealed that PSM conversion is not affected by the size of the halide, only by the steric bulk of the reagent used in these solid-state organic transformations.