Lithium hydroxide (56 mg, 1.3 mmol) was added to a solution of ethyl 2-(4-(tert-butoxycarbonyl)-2-((pyridin-3-yloxy)methyl)piperazin-1-yl)-4-methyloxazole-5-carboxylate (200 mg, 0.448 mmol) in THF (2 mL), MeOH (2 mL), and water (1 mL). After 3 h, 2.5 mL of the reaction mixture was removed and acidified to pH ˜3 with 1 N aqueous HCl. This was diluted with water (15 mL) and extracted with EtOAc (3×30 mL). The combined extracts were dried over Na2SO4, filtered, and concentrated under reduced pressure. The resulting yellow oil was dissolved in DMF (3 mL) and benzylamine (0.027 mL, 0.246 mmol), triethylamine (0.094 mL, 0.672 mmol) and TBTU (108 mg, 0.336 mmol) were added. After 14 h, the reaction mixture was concentrated under reduced pressure and purified by HPLC (5 to 95% MeCN/0.1% TFA in H2O/0.1% TFA gradient). This gave the title compound as a brown solid. LC-MS: RT=7.79 min, [M+H]+=508.9.
