反应详情

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).

1. temperaturewas refluxed for 3 hours under Dean-Stark conditions
2. washwashed with 1N HCl
3. dry with materialThe organic layer was dried (MgSO4)
4. filtrationfiltered
5. customevaporated