反应详情

温度

5 °C

400 g (2.72 mol) of (L)-glutamic acid are dissolved in 2.66 liters of 2N sodium hydroxide solution, the resulting solution is cooled to 5° C. and about 400 ml of benzyl chloroformate (3.6 mol) are run in slowly, dilute sodium hydroxide solution (1 to 2N) being added simultaneously to keep the pH at around 9.0. The mixture is stirred for a few hours, washed with 2×200 ml of ether and acidified to around pH 1. After extraction with ethyl acetate, washing several times with a saturated aqueous solution of sodium chloride, drying and evaporation, a thick oil is obtained which crystallizes from hexane. Weight=500 g; yield=65%; melting point=116/7° C.; H+ titer=99%; [α]D22 =-10.4° (1%, acetone).

1. additionbeing added simultaneously
2. washwashed with 2×200 ml of ether
3. extractionAfter extraction with ethyl acetate
4. washwashing several times with a saturated aqueous solution of sodium chloride
5. customdrying
6. customevaporation
7. customa thick oil is obtained which
8. customcrystallizes from hexane
9. custom7° C.
10. custom[α]D22 =-10.4° (1%, acetone)