反应详情

To a solution of N,N'-bis[2,3-bis(acetyloxy)propyl]-5-[(2,5-dibromo-1-oxopentyl)amino]-2,4,6-triiodo-1,3-benzenedicarboxamide of example 8a (20.7 g, 18.5 mmol) in N,N-dimethylacetamide (200 ml), was added powdered potassium carbonate (20 g, 92 mmol) and the mixture was stirred at room temperature for 5 hours. The resulting slurry was filtered and the filtrate freed of the solvent to obtain a light brown solid, which was redissolved in ethyl acetate (500 ml). The solution was washed with water (2×50 ml) and saturated aqueous sodium chloride (1×100 ml) and then dried over magnesium sulfate. The solvent was removed in vacuo and the crude product (18.1 g) purified by column chromatography over silica gel to obtain pure N,N'-bis[2,3-bis(acetyloxy)propyl]-5-(3-bromo-2-oxo-1-piperidinyl]-2,4,6-triiodo-1,3-benzenedicarboxamide as a white solid (14.04 g, 80% yield), m.p. 232°-35°.

1. filtrationThe resulting slurry was filtered
2. customto obtain a light brown solid, which
3. washThe solution was washed with water (2×50 ml) and saturated aqueous sodium chloride (1×100 ml)
4. dry with materialdried over magnesium sulfate
5. customThe solvent was removed in vacuo
6. customthe crude product (18.1 g) purified by column chromatography over silica gel