Sodium Hydroxide → HCID 86702797, compound

Participants

Reaction Steps

(1R,4S)-dimethyl 7-azabicyclo[2.2.1]heptane-2,3-dicarboxylate (LXIX) (2.46 g, 9.86 mmol) was suspended in water (50 mL) and aq. 1 M NaOH was added to adjust the suspension to pH 12. To this mixture was added a solution of CBz-OSu (2.70 g, 10.84 mmol) in acetone (50 mL) and the reaction mixture was stirred overnight at room temperature. An additional portion of aqueous 4 M NaOH was added to adjust the mixture to pH 14, and the mixture was stirred for another 4 hours at room temperature. The acetone was removed under vacuum and aqueous residue was washed with Et2O (×2). The aqueous layer was acidified to pH 3 using 6 M HCl and extracted with EtOAc (×3). The combined organic layers were dried over MgSO4, filtered and evaporated under vacuum. The crude product was purified by silica gel chromatography using 100% DCM then DCM/MeOH 200/1→100/1 to give (1R,4S)-7-(benzyloxycarbonyl)-7-azabicyclo[2.2.1]heptane-2,3-dicarboxylic acid (L) as a white foam (2.33 g, 7.30 mmol, 74% yield). 1H NMR (CDCl3) δ ppm 1.57 (brs, 2H), 1.75 (brs, 1H), 1.87 (brs, 1H), 3.03 (brs, 1H), 3.60 (brs, 1H), 4.67 (brs, 2H), 5.08 (brs, 2H), 7.03 (brs, 5H), 8.60 (brs, 2H); ESIMS found for C16H17NO6 m/z 342 (M+Na).

Provenance & Evidence