Table 4. Structure–Activity Relationships of the Pyrimidine and Pyridine 2-Position (Labeled as R³ Group).

^aData represent the geometric mean of at least three replicates. See Supporting Information Table S2 for full statistics.

^bData represent the geometric mean of at least two replicates except where superscript 1 is indicated. n.d. = not done.

^cKinetic solubility measured by NMR in HEPES buffer and 5% DMSO at pH 8, and/or where data are shown in brackets, by HPLC in PBS buffer and 1% DMSO at pH 7.4. ^#These compounds showed <10% degradation of BCL6 in single concentration experiments at 10 μM, n = 2.