反应详情

To a suspension of 5-acetamido-N,N'-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophthalamide, prepared as in British Patent No. 1548594, (800 g, 1.07 mol) in propylene glycol (2.4 1) was added 16.5M sodium hydroxide (97.3 ml, 1.61 mol) and then the suspension was stirred at about 70° until the starting material was dissolved. Thereafter the solution was cooled to about 35° and 2-hydroxy-3-methoxypropyl chloride (199.8 g, 1.61 mol) was added. After about 16 h the reaction mixture was heated at about 50° for an additional 8 h. The reaction was quenched by adding hydrochloric acid and then the mixture evaporated in vacuo to dryness. The residue was suspended in methanol (2.3 1 and undissolved salts filtered off. The solution was diluted with water (575 ml) and treated with sufficient amounts of AmberliteRIR-120 cation exchange resin and DowexR 1×4 anion exchange resin to remove inorganic salts. After filtration the solution was treated with charcoal and evaporated to dryness in vacuo. The residue was dissolved in 2 -propanol (3.2 1) by heating and then the solution evaporated to dryness in vacuo. The residue was dissolved in hot 2-propanol (3.2 1) and the solution cooled to -40° whereby the product crystallized. The product was collected on a filter. Yield: 718 g. The crystals (700 g) was dissolved in boiling 2-propanol (2,8 1) and refluxed for 2 days. After some hours crystals insoluble in hot 2-propanol started to crystallize. The mixture was filtered while hot. Yield: 490 g. The crystals were dissolved in water and the solution evaporated to dryness in vacuo.

1. dissolutionwas dissolved
2. temperatureThereafter the solution was cooled to about 35°
3. temperatureAfter about 16 h the reaction mixture was heated at about 50° for an additional 8 h
4. customThe reaction was quenched
5. additionby adding hydrochloric acid
6. customthe mixture evaporated in vacuo to dryness
7. filtrationfiltered off
8. additionThe solution was diluted with water (575 ml)
9. additiontreated with sufficient amounts of AmberliteRIR-120 cation exchange resin and DowexR 1×4 anion exchange resin
10. customto remove inorganic salts
11. filtrationAfter filtration the solution
12. additionwas treated with charcoal
13. customevaporated to dryness in vacuo
14. dissolutionThe residue was dissolved in 2 -propanol (3.2 1)
15. temperatureby heating
16. customthe solution evaporated to dryness in vacuo
17. dissolutionThe residue was dissolved in hot 2-propanol (3.2 1)
18. temperaturethe solution cooled to -40° whereby the product
19. customcrystallized
20. customThe product was collected on a filter
21. dissolutionThe crystals (700 g) was dissolved
22. temperaturerefluxed for 2 days
23. waitAfter some hours crystals insoluble in hot 2-propanol started
24. customto crystallize
25. filtrationThe mixture was filtered while hot
26. dissolutionThe crystals were dissolved in water
27. customthe solution evaporated to dryness in vacuo