Reaction #7376

Reaction equation

lithium bis(trimethylsilyl) amide

tert-butyl (2S)-2-((3S)-3-{[(6-chloro-2-naphthyl)sulfonyl]amino}-2-oxopyrrolidin-1-yl)propanoate

methyl tosylate

→

title compound

tert-Butyl (2S)-2-{(3S)-3-[[(6-chloro-2-naphthyl)sulfonyl](methyl)amino]-2-oxopyrrolidin-1-yl}propanoate

Solvents

THF

Conditions

Workup

1. 1
   Otherto reach room temperature
2. 2
   OtherThe mixture was quenched with sodium acetate (0.074 g)
3. 3
   workup.STIRRINGstirred for 1 h
4. 4
   Otherpartitioned between water and ethyl acetate
5. 5
   WashThe separated organic layer was washed with water
6. 6
   Dryingdried (over magnesium sulphate)
7. 7
   Concentrationconcentrated under reduced pressure
8. 8
   OtherThe residue was purified
9. 9
   WashSPE (silica, eluting with cyclohexane:ethyl acetate 10:1, 8:1, 5:1, 3:1, 2:1,1:1)

Procedure

A solution of tert-butyl (2S)-2-((3S)-3-{[(6-chloro-2-naphthyl)sulfonyl]amino}-2-oxopyrrolidin-1-yl)propanoate (0.1 g) in THF (5 ml) was cooled to −78° C. under nitrogen, and treated with lithium bis(trimethylsilyl) amide (1.0M solution in THF; 0.23 ml), followed by methyl tosylate (0.206 g). The resultant solution was allowed to reach room temperature and stirred for a further 16 h. The mixture was quenched with sodium acetate (0.074 g), stirred for 1 h and partitioned between water and ethyl acetate. The separated organic layer was washed with water, dried (over magnesium sulphate), and concentrated under reduced pressure. The residue was purified using SPE (silica, eluting with cyclohexane:ethyl acetate 10:1, 8:1, 5:1, 3:1, 2:1,1:1) to give the title compound (0.101 g) as a colourless gum.

Source