反应详情

温度

160 °C

Thionyl chloride (217 ml) is slowly added to a stirred suspension of L-glutamic acid (417 g) in dry ethanol (1 L), and the mixture is refluxed for 5 hours. Ethanol is removed under vaccum to give a residue, which is dissolved in water (500 ml). The water solution is made alkaline with saturated sodium carbonate solution and extracted with chloroform (4×200 ml). The chloroform extract is dried (Na2SO4) and evaporated to give crude product (178 g). This material is heated (160° C.) under vaccum (10 mm Hg) for 3 hours. Subsequent distillation gives pure ethyl L-pyroglutamate (126.6 g; b.p. 126° C./0.07 mm Hg; [α]D =-2.15°±0.01 (H2O, c=17.8).

1. temperaturethe mixture is refluxed for 5 hours
2. customEthanol is removed under vaccum
3. customto give a residue, which
4. extractionextracted with chloroform (4×200 ml)
5. extractionThe chloroform extract
6. dry with materialis dried (Na2SO4)
7. customevaporated
8. customto give crude product (178 g)
9. distillationSubsequent distillation