Реакция #50799

Уравнение реакции

N-[2-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-1-oxo-3-phenylpropyl]-O-2-propenyl-L-serine, methyl ester

methylene chloride methanol

methylsulfide

→

N-[2-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-1-oxo-3-phenylpropyl]-O-2-oxoethyl-L-serine, methyl ester

Условия реакции

Обработка

1. 1
   Другоеsparge with a mixture of ozone/oxygen for approximately 10 minutes until a blue color persists
2. 2
   ДругоеSparge with nitrogen for 10 minutes at -78° C.
3. 3
   Другоеto remove excess ozone
4. 4
   Температураto warm to room temperature
5. 5
   Другоеevaporate the solvent in vacuo
6. 6
   workup.DISSOLUTIONdissolve the residue in ethyl acetate (200 mL)
7. 7
   ПромывкаWash with water, saturated sodium chloride
8. 8
   Сушкаdry (Mg SO4)
9. 9
   Другоеevaporate the solvent in vacuo

Методика

Dissolve N-[2-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-1-oxo-3-phenylpropyl]-O-2-propenyl-L-serine, methyl ester (13 g, 29.8 mmol ) in methylene chloride/methanol (10:1, 220 mL). Cool to -78° C. and sparge with a mixture of ozone/oxygen for approximately 10 minutes until a blue color persists. Sparge with nitrogen for 10 minutes at -78° C. to remove excess ozone. Treat with methylsulfide (60 mL, 0.82 mol) and allow to warm to room temperature. Stir at room temperature for 2.5 hours, evaporate the solvent in vacuo and dissolve the residue in ethyl acetate (200 mL). Wash with water, saturated sodium chloride, dry (Mg SO4) and evaporate the solvent in vacuo to give the intermediate N-[2-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-1-oxo-3-phenylpropyl]-O-2-oxoethyl-L-serine, methyl ester as a foam (13.6 g).

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