反应详情

温度

4 °C

A solution of 374 g (1.48 mol) (2S,4R)-4-Hydroxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester in 1.61 CH2Cl2 was treated with 680 g (2.6 mol) triphenylphosphine, cooled to 3-5° C. and treated in 10 min with 1.24l (12.8 mol) CCl4, after 2 h at this temperature cooling was stopped, the reaction temperature was raised to 35° C. over a period of 2 h. It was cooled down to 20° C. and stirred for further 45 min. After addition of 4l of n-heptane, the reaction was evaporated to 2.9l, cooled to 0° C., filtered, the residue was treated twice the same way, the third time by dissolving the residue again in 2 of CH2Cl2. The solvents were evaporated and filtered through silicagel with hexane/tert.-buthyl-methylether 9:1 as eluent. Evaporation of the solvents gave 347 g (89%) of (2S,4S)-4-Chloro-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester, MS: 246 (MH+).

1. temperaturecooling
2. temperaturethe reaction temperature was raised to 35° C. over a period of 2 h
3. temperatureIt was cooled down to 20° C.
4. customthe reaction was evaporated to 2.9l
5. temperaturecooled to 0° C.
6. filtrationfiltered
7. additionthe residue was treated twice the same way
8. dissolutionthe third time by dissolving the residue again in 2 of CH2Cl2
9. customThe solvents were evaporated
10. filtrationfiltered through silicagel with hexane/
11. customEvaporation of the solvents