A method for preparing a contrast agent precursor is revealed. The method includes several steps. First dissolve di-tert-butyl 2,2′-(1,4,7-triazacyclononane-1,4-diyl)diacetate, benzyl-2-bromoacetate and an alkaline compound in a first solvent to perform a bimolecular nucleophilic substitution reaction and get a product. Then dissolve the product in a second solvent to get a solution and adjust the pH value of the solution. Next add an organic solvent when the solution becomes acid and then remove a first organic layer that contains the organic solvent. Adjust the solution to become an alkaline solution and add the organic solvent again to get a second organic layer containing the organic solvent. The second organic layer contains the final product, di-tert-butyl 2,2′-7-[2-(benzyloxy)-2-oxyethyl-(1,4,7-triazacyclononane-1,4-diyl}-diacetate.
揭示了一种制备对比剂前体的方法。该方法包括几个步骤。首先,在第一溶剂中溶解双叔丁基2,2'-(
1,4,7-三氮杂环壬烷-1,4-二基)二
乙酸酯,苄基-2-
溴乙酸酯和碱性化合物,进行双分子亲核取代反应并得到产物。然后在第二溶剂中溶解产物以得到溶液,并调节溶液的pH值。接下来,当溶液变酸时添加有机溶剂,然后去除含有有机溶剂的第一有机层。将溶液调节为碱性溶液,并再次添加有机溶剂以得到含有有机溶剂的第二有机层。第二有机层包含最终产物,即双叔丁基2,2'-7-[2-(苄氧基)-2-氧乙基-(
1,4,7-三氮杂环壬烷-1,4-二基)}-二
乙酸酯。