反应详情

A solution of 5-[3-(acetyloxy)-2-oxo-1-piperidinyl]-N,N'-bis[2,3-bis(acetyloxy)propyl]-2,4,6-triiodo-1,3-benzenedicarboxamide of example 8c (4 g, 4.3 mmol) in methanol (20 ml) was treated with a solution of sodium methoxide in methanol, prepared from sodium (30 mg, 1.3 mmol) and anhydrous methanol (20 ml), and the mixture was stirred at room temperature for 2 hours. The pH of the solution was adjusted down to 7 by the addition of Dowex-50 (H+) resin. The mixture was filtered and the filtrate was freed of the solvent to obtain the crude product. Purification by low pressure reverse phase column chromatography over the CHP-20P resin furnished analytically pure N,N'-Bis[2,3-dihydroxypropyl)-5-(3-hydroxy-2-oxo-1-piperidinyl)-2,4,6-triiodo-1,3-benzenedicarboxamide as a snow-white glassy solid (2.3 g, 78% yield).

1. additionThe pH of the solution was adjusted down to 7 by the addition of Dowex-50 (H+) resin
2. filtrationThe mixture was filtered
3. customto obtain the crude product
4. customPurification by low pressure reverse phase column chromatography over the CHP-20P resin