To a stirred solution of 6 (1.4 g, 3.1 mmol) in acetonitrile (50 mL) was added potassium carbonate(s) (0.857 g, 6.2 mmol), followed by methyl 4-bromobutyrate (1.1224 g, 6.2 mmol) before leaving to stir overnight at reflux. The reaction was cooled and partitioned between ethyl acetate (50 mL) and water (50 mL). The organic phase was collected, and the aqueous layer was extracted with ethyl acetate (3 × 25 mL). The organics were combined and washed with brine (100 mL), dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. Purification by flash column chromatography, eluting with 0 -5% methanol in dichloromethane with 0.5% NH4OH, afforded the title compound as a clear oil (1.12 g, 70% To a stirred solution of 9 (100 mg, 0.19 mmol, 1 eq.) and HATU (83.7 mg, 0.22 mmol, 1.2 eq.) in DMF (mL) was added triethylamine (26.5 µL, 0.19 mmol, 1.2 eq.) followed by 2-methoxyethylamine (14.3 mg, 0.19 mmol, 1 eq.) before leaving the reaction to stir at ambient temperature overnight. The mixture was partitioned between dichloromethane (25 mL) and water (25 mL). The organic layer was collected and washed with saturated aqueous sodium hydrogen carbonate solution (25 mL) and brine (3 × 10 mL), dried over anhydrous magnesium sulfate and concentrated under reduced pressure. Purification by flash column chromatography, eluting with 0 -10% methanol in dichloromethane with 0.5% NH4OH, afforded the title compound as a colorless oil (88 mg, 79% . After stirring at ambient temperature overnight, the reaction mixture was partitioned between ethyl acetate (500 mL) and water (2 L). The organic phase was separated, and the aqueous component was extracted with ethyl acetate (3 × 300 mL). The organic extracts were combined and successively washed with saturated aqueous sodium hydrogen carbonate solution (150 mL) and brine (150 mL), before being dried over anhydrous magnesium sulfate and concentrated under reduced pressure.