Reaktion #1375819

Reaktionsgleichung

1,4,7-tris-(carboxymethyl)-1,4,7, 10-tetraazacyclododecane

(2-bromoethyl)-tert-butyl ether

potassium carbonate

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title compound

Ausbeute 65.0%

10-(4,4-Dimethyl-3-oxa-pentyl)-1,4,7-tris-(carboxymethyl)-1,4,7,10-tetraazacyclododecane

Ausbeute 65.0%

Lösungsmittel

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenIt is concentrated by evaporation in a vacuum
2. 2
   workup.DISSOLUTIONthe residue is dissolved in 100 ml of water
3. 3
   workup.ADDITIONby adding 12 N hydrochloric acid
4. 4
   WaschenIt is eluted with 2 l of water, which
5. 5
   EinengenThis solution is concentrated by evaporation in a vacuum
6. 6
   workup.DISSOLUTIONthe residue is dissolved in 100 ml of water
7. 7
   workup.ADDITIONenough cation exchanger IR-120 is added in portions up to pH 3.5
8. 8
   FiltrationThe solution is filtered
9. 9
   Sonstigefreeze-dried

Vorschrift

5 g (14.43 mmol) of 1,4,7-tris-(carboxymethyl)-1,4,7, 10-tetraazacyclododecane is stirred in 75 ml of dimethylformamide for 18 hours with 3.14 g (17.35 mmol) of (2-bromoethyl)-tert-butyl ether and 6.50 g of potassium carbonate at 95° C. It is concentrated by evaporation in a vacuum and the residue is dissolved in 100 ml of water, the pH is adjusted to 2 by adding 12 N hydrochloric acid and the solution is put on a column of 320 ml of cation exchanger IR-120 (H+ form). It is eluted with 2 l of water, which is discarded, then with 2 l of 0.5 N ammonia solution. This solution is concentrated by evaporation in a vacuum, the residue is dissolved in 100 ml of water. With stirring, enough cation exchanger IR-120 is added in portions up to pH 3.5. The solution is filtered and freeze-dried and 4.19 g of the title compound is obtained as white solid with a water content of 6.3%.

Quelle