反应详情

300 g (0.475 mol) of 5-amino-2,4,6-triiodoisophthalic acid mono-(2,3-dihydroxy-propyl) amide is suspended in 1.4 liter of ethyl acetate, mixed with 178.07 g (1.74 mol) of acetic anhydride and 5.7 g (47.5 mmol) of 4-dimethylaminopyridine and the mixture is heated to boiling. The suspension changes into a solution from which the product quickly crystallizes out in the boiling heat. The acetylation is completed after 1 hour. The excess acetic anhydride is reacted to ethyl acetate by addition of ethanol, cooled to room temperature, the crystallizate is suctioned off, washed with ethyl acetate and dried in a vacuum at 50° C. The yield is 300.2 g (0.42 mol)=88.4% of theory.

1. temperaturethe mixture is heated to boiling
2. customquickly crystallizes out in the
3. temperatureboiling heat
4. customThe excess acetic anhydride is reacted to ethyl acetate by addition of ethanol
5. washwashed with ethyl acetate
6. customdried in a vacuum at 50° C