Phthalic Anhydride → (2S)-2-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-propionic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsschritte

A suspension of (2S) alanine tert-butyl ester hydrochloride (2.05 g, 11.2 mmol), diisopropylethylamine (1.83 mL, 10.6 mmol) and phthalic anhydride (1.48 g, 10 mmol) in toluene (10 mL) was refluxed for 3 hours under Dean-Stark conditions. The reaction was cooled to room temperature, diluted with Et2O, washed with 1N HCl and then with aq.sat. NaHCO3. The organic layer was dried (MgSO4), filtered and evaporated to afford the sub-title compound as a white powder (2.465 g, 90%): 1H NMR (400 MHz CDCl3) δ 1.45 (9H, s), 1.68 (3H, d), 4.90 (1H, q), 7.75 (2H, d), 7.88 (2H, d).

Herkunft & Nachweise