Chloride → 5-Amino-2,4,6-triiodo-N~1~,N~3~-dimethylbenzene-1,3-dicarboxamide

Participants

Reaction Steps

To a solution of 3-amino-5-[N-(2-hydroxyethyl)acetamido]-2,4,6-triiodo-N-methylbenzamide (II; 50.32 g.; 0.08 mole) dissolved in dimethylacetamide (252 ml.) was added in one portion 2,3,4,5,6-O-pentaacetylgluconyl chloride (101.88 g.; 0.24 mole; prepared by the method of C. E. Braun and C. D. Cook, Org. Syn., 41, 79 (1961)). After being stirred for six days at room temperature, the reaction mixture was poured into a mixture of dimethylacetamide (510 ml.) and water (680 ml.). The mixture was stirred for 2 hours, after which it was extracted with chloroform (3×340 ml.). The combined chloroform extracts were washed with 5% aqueous bicarbonate (2×340 ml.) and water (340 ml.), dried over sodium sulfate and evaporated under reduced pressure to give III as an oil, 132.75 g. (>100% due to the presence of dimethylacetamide as shown by the nuclear magnetic resonance spectrum). The product was homogeneous by thin-layer chromatography (ethyl acetate-acetic acid, 98:2), and the nuclear magnetic resonance spectrum was consistent with the assigned structure. The product was hydrolyzed without further purification.

Provenance & Evidence