反应详情

To 28.2 g N-carbobenzyloxy-γ-tert.butyl-L-glutamic acid-dicyclohexyl ammonium salt, 360 ml ethyl acetate and 49.5 ml solution of dimethylaminoethylchloride in the amount of 11.7 g, which stoichiometrically corresponds to two times the molar volume, in benzene were added to be subjected to flux in oil bath at 90° C. for 16 hrs. After cooling, precipitated dicyclohexyl ammonium chloride was filtered off and ethyl acetate phase in the filtrate was washed with diluted hydrochloride to remove excessive dimethylaminoethylchloride contained therein. The filtrate was further washed with 10% aqueous solution of hydrogen sodium bicarbonate so as to remove the unreacted starting material and then with saturated brine to be neutral, which was then treated with sulfuric sodium anhydride for dehydration to be dried and subjected to reduced pressure distillation so as to distill off ethyl acetate and obtain the Intermediate I, N-carbobenzyloxy-γ-tert.butyl-L-glutamic acid-α-dimethylaminoethyl ester in the amount of 21.5 g (yield; 96.8%).

1. temperatureAfter cooling
2. customprecipitated dicyclohexyl ammonium chloride
3. filtrationwas filtered off
4. washethyl acetate phase in the filtrate was washed with diluted hydrochloride
5. customto remove excessive dimethylaminoethylchloride
6. washThe filtrate was further washed with 10% aqueous solution of hydrogen sodium bicarbonate so as
7. customto remove the
8. additionwhich was then treated with sulfuric sodium anhydride for dehydration
9. customto be dried
10. distillationsubjected to reduced pressure distillation so as
11. distillationto distill off ethyl acetate