A selective HDAC1/3 inhibitor (IC50s = 199 and 69 nM for HDAC1 and HDAC3, respectively); selective for HDAC1 and HDAC3 (IC50 = >1.59 μM for HDAC2, 4, 5, 7, and 8 in a cell-free enzyme assay); improves the metabolic deficit exhibited by murine striatal cells isolated from HdhQ111 knock-in mice in a dose-dependent manner; reduces eye neurodegeneration in D. melanogaster model of Huntington's disease; prevents formation of Htt aggregates in the brain and reduces the cognitive deficits in the N171-82Q mouse model of Huntington's disease