反应详情

温度

0 °C

A solution of 5.0 g (0.025 mol) L-methionine methyl ester hydrochloride is dissolved in 30 ml of dichloromethane. The solution is cooled to 0° C. and 4.42 ml (0.028 mol) of triethylamine is added dropwise over a ten minute period. The mixture is stirred 15 minutes, filtered, and a mixture of the following is added in a single addition: 6.32 g (0.03 mol) of dicyclohexylcarbodiimide; 200 mg (0.0016 mol) of 4-dimethylaminopyridine; 3.85 g (0.025 mol) of 5-oxo-2-pyrrolidinepropanoic acid. The reaction is allowed to warm to room temperature and stirred for 24 hours. The solids are removed by filtration and are washed with 15 ml of 0° C. dichloromethane. The filtrate is concentrated at reduced pressure to an oil. The oil is chromatographed over silica gel using 19:1 dichloromethanemethanol for elution. Concentration at reduced pressure followed by heating at 0.1 mm pressure and 60° C. yields crystalline analytically pure N-[1-oxo- 3-(5-oxo-2-pyrrolidinyl)propyl]-L-methionine, methyl ester with a melting point of 98°-100° C.

1. filtrationfiltered
2. additiona mixture of the following
3. additionis added in a single addition
4. temperatureto warm to room temperature
5. stirringstirred for 24 hours
6. customThe solids are removed by filtration
7. washare washed with 15 ml of 0° C. dichloromethane
8. concentrationThe filtrate is concentrated at reduced pressure to an oil
9. customThe oil is chromatographed over silica gel using 19:1 dichloromethanemethanol for elution
10. concentrationConcentration at reduced pressure
11. temperatureby heating at 0.1 mm pressure and 60° C.