反应详情

N,N′-Bis(2,2-dimethyl-1,3-dioxolane-4-carbonyl)-3,5-diamino-2,4,6-triiodobenzylacetate (408 mg, 0.50 mmol) was dissolved in a mixture of dimethylacetamide (4 ml) and DMSO (4 ml) containing Cs2CO3 (1.80 g, 5.52 mmol) and 2,2-dimethyl-1,3-dioxolane-4-carboxylic acid chloride (2.0 ml). After stirring for 8 days, aqueous NaH2PO4 (100 ml) was added and the mixture was extracted with diethyl ether (2×150 ml). The combined organic phases were washed with water (6×100 ml), dried (Na2SO4) and evaporated. The residue was dissolved in a mixture of methanol (10 ml) and water (10 ml) and pH was adjusted to 12 with aqueous NaOH. After stirring for 2 h, concentrated HCl (1.0 ml) was added and stirring was continued for 16 h. After neutralization, the solvents were evaporated and the residue was purified by preparative HPLC. Yield: 149 mg (39%).

1. extractionthe mixture was extracted with diethyl ether (2×150 ml)
2. washThe combined organic phases were washed with water (6×100 ml)
3. dry with materialdried (Na2SO4)
4. customevaporated
5. dissolutionThe residue was dissolved in a mixture of methanol (10 ml) and water (10 ml) and pH
6. stirringAfter stirring for 2 h
7. additionconcentrated HCl (1.0 ml) was added
8. stirringstirring
9. waitwas continued for 16 h
10. customAfter neutralization, the solvents were evaporated
11. customthe residue was purified by preparative HPLC