A BCL6 inhibitor (IC50 = ~35 μM); selective for BCL6 over a panel of 50 kinases at 10 μM; reduces recruitment of the BCL6 corepressor proteins SMRT and BCOR to the BCL6 target loci CDKN1A, CD69, and CXCR4 in a ChIP assay at 50 μM; represses growth of Farage, SUDLH-6, DOHH-2, OCI-Ly7, RCK8, SUDHL-4, OCI-Ly1, and SC-1 BCL6-dependent cell lines (GI50s = 16-54 μM); reduces tumor volume in an HBL-1 large B cell lymphoma mouse xenograft model at 50 mg/kg