Benzyl Bromide → (1R,3S,5R)-2-Aza-bicyclo[3.1.0]hexane-2,3-dicarboxylic acid 3-benzyl ester 2-tert-butyl ester

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Reaction Steps

To a solution of (1R,3S,5R)-2-azabicyclo[3.1.0]hexane-2,3-dicarboxylic acid 2-tert-butyl ester (2.5 g, 11.0 mmol) and Cs2CO3 (3.94 g, 12.1 mmol) in DMF (50 mL) at 0° C. benzylbromide (2.26 g, 13.2 mmol) was added dropwise. The reaction mixture was stirred overnight at RT under a nitrogen atmosphere. DMF was evaporated. The residue was dissolved in EtOAc and washed with a sat. aq. solution of NaHCO3, the layers were separated and the aqueous phase was extracted with EtOAc (×2). The combined organic extracts were dried over Na2SO4, filtered and concentrated. The crude residue was purified by flash column chromatography on silica gel (c-hexane/EtOAc 100:0 to 0:100) to give the desired material as a colorless oil. MS (LCMS): 318.2 [M+H]+; tR (HPLC conditions b): 2.23 min.

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