Hydrochloric Acid → 6-[2-(4-Bromo-phenyl)-2-oxo-ethylcarbamoyl]-5-aza-spiro[2.4]heptane-5-carboxylic acid benzyl ester

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Reaction Steps

5-Aza-spiro[2.4]heptane-5,6-dicarboxylic acid 5-benzyl ester (361 mg, 1.25 mmol) was dissolved in MeOH (10 mL) and LiOH (1 M in H2O, 5 mL, 5 mmol) was added. After stirring for 15 hours at room temperature, the reaction mixture was poured into 10% HCl and the aqueous phase was extracted 3× with DCM. The combined organics were dried over MgSO4, filtered and concentrated. The residue was treated with 2-Amino-1-(4-bromo-phenyl)-ethanone hydrochloride (344 mg, 1.38 mmol), HATU (525 mg, 1.38 mmol) and DMF (14 mL). The suspension was stirred at 0° C. for 21 minutes before DIPEA (0.72 mL, 4.1 mmol) was added dropwise. Immediately after addition, the reaction mixture was warmed to room temperature. 40 minutes later the mixture was diluted with EtOAc. The organic layer was washed with saturated aqueous NaHCO3 and brine, then dried over MgSO4, filtered and concentrated. The crude residue was purified by silica column chromatography (30% to 50% EtOAc/hexane) to afford 6-[2-(4-Bromo-phenyl)-2-oxo-ethylcarbamoyl]-5-aza-spiro[2.4]heptane-5-carboxylic acid benzyl ester (589 mg, 100%).

Provenance & Evidence