反应详情

Hydroxylamine Free base (50% aqueous solution, 45.0 g, 0.68 mol) was added dropwise to a solution of diethyl maleate (100.0 g, 0.56 mol) in ethanol (100 mL) in a 3-neck flask blanketed with nitrogen. The reaction temperature was maintained below 55° C. with an ice bath. The mixture was stirred for 30 minutes. The reaction mixture was concentrated under reduced pressure to give crude diethyl N-hydroxyaspartate (103 g, 89% yield). The product was analyzed by nuclear magnetic resonance spectroscopy (NMR) and shown to be at least 95% pure. NMR (acetone-d6) 1.20 (m, 6H), 2.59 (dd, J 6.8, 16.1 Hz, 1H), 2.76 (dd, J 6.8, 16.1 Hz, 1H), 3.89 (t, J 6.8 Hz, 1H), and 4.11 (m, 4H).

1. temperatureThe reaction temperature was maintained below 55° C. with an ice bath
2. concentrationThe reaction mixture was concentrated under reduced pressure