Reaction #7374

Reaction equation

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

lithium bis(trimethylsilyl) amide

Methanol

1-bromo-2-butanone

→

title compound

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

Solvents

THF

Conditions

Workup

1. 1
   Otherto reach room temperature
2. 2
   Concentrationthe resultant solution concentrated under reduced pressure
3. 3
   OtherThe residue was purified
4. 4
   WashSPE (silica, eluting with cyclohexane:ethyl acetate 10:1, 5:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:5, ethyl acetate and methanol:ethyl acetate 1:9)

Procedure

A solution of tert-butyl (2S)-2-((3S)-3-{[(6-chloro-2-naphthyl)sulfonyl]amino}-2-oxopyrrolidin-1-yl)propanoate (0.07 g) in THF (2 ml) was cooled to −78° C. under nitrogen, and treated with lithium bis(trimethylsilyl) amide (1.0M solution in THF; 0.186 ml), followed by 1-bromo-2-butanone (0.08 ml). The resultant solution was allowed to reach room temperature and stirred for a further 72 h. Methanol (1 ml) was added and the resultant solution concentrated under reduced pressure. The residue was purified using SPE (silica, eluting with cyclohexane:ethyl acetate 10:1, 5:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:5, ethyl acetate and methanol:ethyl acetate 1:9) to give the title compound (0.07 g) as a gum.

Source