Sodium hydride (0.557 g, 13.93 mmol) was added portionwise to 7-amino-2-methyl-4-(4-propan-2-ylpiperazin-1-yl)-3H-isoindol-1-one (1.004 g, 3.48 mmol), in THF (30 mL) at room temperature under an atmosphere of nitrogen. The resulting suspension was stirred at room temperature for 30 minutes and then 4,6-dichloropyridine-3-carbonitrile (0.602 g, 3.48 mmol) was added portionwise and the mixture heated overnight at 60° C. The mixture was allowed to cool to room temperature and then diluted with EtOAc (50 mL). The mixture was washed sequentially with water (50 mL), a saturated solution of NaHCO3 (50 mL), water (25 mL) and finally with a saturated solution of NaCl (20 mL). The mixture was filtered and the organic layer separated, dried over Na2SO4 and then evaporated. The residue was triturated in Et2O and MeOH and the mixture filtered. The filtrate was evaporated and the residue purified by chromatography on silica, eluting with a gradient of 5-10% MeOH in CH2Cl2. Fractions containing product were combined and evaporated to leave 6-chloro-[[2-methyl-3-oxo-7-(4-propan-2-ylpiperazin-1-yl)-1H-isoindol-4-yl]amino]pyridine-3-carbonitrile (316 mg, 21% yield); 1H NMR spectrum: (300 MHz, DMSO) δ 1.02 (6H, d), 2.60 (4H, t), 2.70 (1H, t), 3.02-3.08 (7H, m), 4.51 (2H, s), 7.04 (1H, d), 7.15 (1H, dd), 7.44 (1H, dd), 8.53 (1H, d), 9.68 (1H, s); Mass spectrum: m/z (ESI+) (M+H)+=425.30.
