3,4-Dichloro-5-methyl-1H-pyrrole-2-carboxylic acid (Intermediate 3, 164 mg, 0.84 mmol) was dissolved in anhydrous THF (3 ml). 2-Chloro-6-(4-hydroxypiperidin-1-yl)isonicotinonitrile (Intermediate 26), 200 mg, 0.84 mmol) was added, then DEAD (133 μl, 0.84 mmol) was added dropwise followed by triphenylphosphine (221 mg, 0.84 mmol). The mixture was stirred at room temperature for 18 h. The mixture was concentrated, filtered and purified by semi-preparative reverse phase HPLC eluting with CH3CN/water (0.1% TFA). (135 mg).
