A mixture trifluoromethanesulfonic acid 4-[2-methyl-4-(2,4,6-trimethylphenylamino)-pyrimidine-5-sulfonyl]-phenyl ester (72 mg, 0.14 mmol), prepared by the method described in Example 22, pyridine-4-boronic acid (34 mg, 0.28 mmol), 2 M Na2CO3 (1.0 mL, 2.0 mmol) and DME (2 mL) was deoxygenated with N2 for 10 min, and then Pd(PPh3)2Cl2 (20 mg, 0.028 mmol) and PPh3 (15 mg, 0.056 mmol) were added. The mixture was heated at reflux under N2 for 2 h and then cooled to room temperature. Saturated aqueous NaHCO3 was added, and the mixture was extracted three times with EtOAc. The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified by chromatography on silica gel (50:50 hexanes/EtOAc) to provide the desired product (38 mg, 61%) as a white solid: mp 232–234° C.; 1H NMR (500 MHz, CDCl3) δ 8.79 (s, 1H), 8.73 (d, J=4.5 Hz, 2H), 8.28 (br s, 1H), 8.13 (d, J=8.4 Hz, 2H), 7.78 (d, J=8.4 Hz, 2H), 7.48 (d, J=4.5 Hz, 2H), 6.92 (s, 2H), 2.40 (s, 3H), 2.31 (s, 3H), 2.03 (s, 6H); APCI MS m/z 445 [(M+H)+, calcd for C25H25N4O2S, 445.2].
