In THF (10 mL) were dissolved 4-((3-chloro-4-methoxybenzyl)amino)-2-(methyl sulfinyl)-N-(pyrimidin-2-ylmethyl)pyrimidine-5-formamide (152 mg, 0.34 mmol), 2-methyl-2,7-diazaspiro[3.5]nonane (70 mg, 0.50 mmol) and HATU (383 mg, 1 mmol). Triethylamine (68 mg, 0.67 mmol) was added dropwisely. The reaction was conducted at ambient temperature for 4 h, followed by addition of water (50 mL) and extraction with DCM. The organic phase was dried over sodium sulfate and purified by silica gel column chromatography (DCM/methanol=20/1) to give 4-((3-chloro-4-methoxybenzyl)amino)-2-(7-methyl-2,7-diazaspiro[3.5]nonan-2-yl)-N-(pyrimidin-2-ylmethyl)pyrimidine-5-formamide as a white solid (16 mg, 9% yield).
