Reaktion #2275687

Reaktionsgleichung

triethylamine

acetic acid 2-acetoxy-1-(3,5-bis-chlorocarbonyl-2,4,6-triiodo-phenylcarbamoyl)-ethyl ester

2-[(2,2-Dimethyl-[1,3]dioxolan-4-yl-methyl)-amino]-ethanol

→

desired product

Ausbeute 38.5%

Acetic acid 2-acetoxy-1-{3-chlorocarbonyl-5-[(2,2-dimethyl-[1,3]-dioxolan-4-ylmethyl)-(2-hydroxy-ethyl)-carbamoyl]-2,4,6-triiodo-phenylcarbamoyl}-ethyl ester

Ausbeute 38.5%

Lösungsmittel

DMAC

DMAC

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONpoured over icewater (0.75 liter)
2. 2
   SonstigeA white precipitate formed
3. 3
   SonstigeThis was collected
4. 4
   Waschenwashed with cold water
5. 5
   workup.DISSOLUTIONThe filter cake was then dissolved in ethyl acetate
6. 6
   Waschenwashed with brine
7. 7
   SonstigeThe organics were collected
8. 8
   Trocknendried over MgSO4
9. 9
   Filtrationfiltered
10. 10
    Sonstigeevaporated to dryness
11. 11
    SonstigeThe product was purified by silica column chromatography
12. 12
    Wascheneluting with Petroleum ether/ethyl acetate
13. 13
    WaschenTwo peaks closely eluting at 80% ethyl acetate

Vorschrift

To a ice cooled solution of acetic acid 2-acetoxy-1-(3,5-bis-chlorocarbonyl-2,4,6-triiodo-phenylcarbamoyl)-ethyl ester (20 g, 0.026 mol) in anhydrous DMAC (20 ml) were added dropwise a solution of 2-[(2,2-Dimethyl-[1,3]dioxolan-4-yl-methyl)-amino]-ethanol (4.6 g, 0.026 mol) in DMAC (20 mL) followed by triethylamine (˜3 g). The mixture was stirred at room temperature for 24 h and then poured over icewater (0.75 liter). A white precipitate formed. This was collected and washed with cold water. The filter cake was then dissolved in ethyl acetate and washed with brine. The organics were collected, dried over MgSO4, filtered and evaporated to dryness. The product was purified by silica column chromatography eluting with Petroleum ether/ethyl acetate. Two peaks closely eluting at 80% ethyl acetate were analysed by NMR and mass spec, and show to both contain the desired material. These were combined post analysis to give the desired product (10 mmol, Yield=38%).

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