Reaktion #61098

Reaktionsgleichung

diphosgene

(2S,3S)-2-{(R)-2-amino-2-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-acetylamino}-3-phenyl-N-(4-propionyl-thiazol-2-yl)-butyramide

diisopropylethylamine

→

(2S,3S)-2-{2,5-dioxo-4-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-imidazolidin-1-yl}-3-phenyl-N-(4-propionyl-thiazol-2-yl)-butyramide

Ausbeute 35.9%

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigepartitioned between ethyl acetate and water
2. 2
   SonstigeThe organic layer was separated
3. 3
   Trocknendried over sodium sulfate
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated in vacuo
6. 6
   SonstigeThe residue was purified by chromatography over silica gel
7. 7
   Wascheneluted first with ethyl acetate
8. 8
   Waschengradient eluted with dichloromethane containing from 0 to 10% methanol
9. 9
   SonstigePrecipitation of the isolated product from dichloromethane with an excess of hexanes

Vorschrift

Crude (2S,3S)-2-{(R)-2-amino-2-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-acetylamino}-3-phenyl-N-(4-propionyl-thiazol-2-yl)-butyramide (≈0.16 mmol) was dissolved in tetrahydrofuran (10 mL) that contained diisopropylethylamine (142 μL, 105 mg, 0.81 mmol) and was transferred via cannula to a solution of diphosgene (14 μL, 23 mg, 0.12 mmol) in tetrahydrofuran (15 mL) at 0° C. The reaction mixture was stirred for 20 minutes and then partitioned between ethyl acetate and water. The organic layer was separated and dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by chromatography over silica gel eluted first with ethyl acetate and then gradient eluted with dichloromethane containing from 0 to 10% methanol. Precipitation of the isolated product from dichloromethane with an excess of hexanes gave (2S,3S)-2-{2,5-dioxo-4-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-imidazolidin-1-yl}-3-phenyl-N-(4-propionyl-thiazol-2-yl)-butyramide as a white solid (26 mg, 27%).

Quelle