Reaction #2275687

Reaction equation

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

Yield 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

Yield 38.5%

Solvents

DMAC

DMAC

Conditions

Workup

1. 1
   workup.ADDITIONpoured over icewater (0.75 liter)
2. 2
   OtherA white precipitate formed
3. 3
   OtherThis was collected
4. 4
   Washwashed with cold water
5. 5
   workup.DISSOLUTIONThe filter cake was then dissolved in ethyl acetate
6. 6
   Washwashed with brine
7. 7
   OtherThe organics were collected
8. 8
   Dryingdried over MgSO4
9. 9
   Filtrationfiltered
10. 10
    Otherevaporated to dryness
11. 11
    OtherThe product was purified by silica column chromatography
12. 12
    Washeluting with Petroleum ether/ethyl acetate
13. 13
    WashTwo peaks closely eluting at 80% ethyl acetate

Procedure

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%).

Source