Reacción #2275687

Ecuación de reacción

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

Rendimiento 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

Rendimiento 38.5%

Disolventes

DMAC

DMAC

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONpoured over icewater (0.75 liter)
2. 2
   OtroA white precipitate formed
3. 3
   OtroThis was collected
4. 4
   Lavadowashed with cold water
5. 5
   workup.DISSOLUTIONThe filter cake was then dissolved in ethyl acetate
6. 6
   Lavadowashed with brine
7. 7
   OtroThe organics were collected
8. 8
   Secadodried over MgSO4
9. 9
   Filtraciónfiltered
10. 10
    Otroevaporated to dryness
11. 11
    OtroThe product was purified by silica column chromatography
12. 12
    Lavadoeluting with Petroleum ether/ethyl acetate
13. 13
    LavadoTwo peaks closely eluting at 80% ethyl acetate

Procedimiento

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%).

Fuente