反应详情

温度

60 °C

To a 1 L 3-necked flask equipped with a thermometer and a magnetic stirrer were added 4.90 g of L-glutamic acid γ-methyl ester (Sigma) and 200 mL of water. The solution was heated to 60° C., treated with 6.40 g of NaHCO3 followed by 5.20 mL of benzyl chloroformate (Aldrich) and allowed to cool to RT with vigorous stirring. After 4 h the reaction mixture was extracted with ethyl ether (4×100 mL) and the ether extracts were discarded. The aqueous solution was acidified to a congo red endpoint by addition of concentrated HCl. An oily emulsion resulted which was extracted with CH2Cl2 (4×60 mL). The combined organic extracts were washed with 0.05 N aqueous HCl (2×60 mL), dried over anhydrous Na2SO4 and concentrated in vacuo to afford 8.23 g (92%) of N-((benzyloxy)carbonyl)-5-O-methyl-L-glutamic acid as a white crystalline solid, m.p. 61-63° C.

1. customTo a 1 L 3-necked flask equipped with a thermometer and a magnetic stirrer
2. temperatureto cool to RT with vigorous stirring
3. extractionAfter 4 h the reaction mixture was extracted with ethyl ether (4×100 mL)
4. additionThe aqueous solution was acidified to a congo red endpoint by addition of concentrated HCl
5. customAn oily emulsion resulted which
6. extractionwas extracted with CH2Cl2 (4×60 mL)
7. washThe combined organic extracts were washed with 0.05 N aqueous HCl (2×60 mL)
8. dry with materialdried over anhydrous Na2SO4
9. concentrationconcentrated in vacuo