A mixture of 2-amino-5-bromo-isonicotinonitrile (1.0 g, 5.1 mmol, prepared according to Example 3, Step 2.1), 2,4-dichloro-benzeneboronic acid (1.45 g, 7.6 mmol), Pd(PPh3)4 (292 mg, 0.25 mmol) and Na2CO3 (2.0 M solution in water, 8.8 mL) in DME (10 mL) was refluxed for 2 h under an inert atmosphere of argon. The reaction mixture was cooled to RT, diluted in AcOEt and washed with water. The organic layer was dried over Na2SO4, filtered, and evaporated. The residue was purified by Combi-Flash Companion™ (Isco Inc.) column chromatography (SiO2; gradient elution, [hexane/DCM 1:1]/TBME 95:5→3:7) to yield the title compound (880 mg, 3.3 mmol, 66%). MS: 264 [M+1]+; HPLC: AtRet=1.73; TLC: RF 0.31 (hexane/DCM/TBME 1:1:2).
