N,N'-Bis-[2,3-diacetyloxypropyl]-5-[3-bromo-2-oxo-1-pyrrolidinyl]2,4,6-triiodo-1,3-benzenedicarboxamide → N,N'-bis-[2,3-diacetyloxypropyl]-5-[3-acetyloxy-2-oxo-1-pyrrolidinyl]-2,4,6-triiodo-1,3-benzenedicarboxamide

Participants

Reaction Steps

N,N'-Bis-[2,3-diacetyloxypropyl]-5-[3- bromo-2-oxo-1-pyrrolidinyl]-2,4,6-triiodo-1,3-benzenedicarboxamide of example 5a, (6.43 g, 6.30 mmol) was dissolved in glacial acetic acid (63 ml) and then treated with silver acetate (4.21 g, 25.21 mmol) at reflux under nitrogen for 26 hours. The reaction mixture was cooled to room temperature and the solids filtered off. The solvent was evaporated in vacuo and the residue was partitioned between ethyl acetate and brine. The organic layer was dried and removal of the solvent afforded the crude product as a colored foam. Purification by silica gel flash chromatography furnished N,N'-bis-[2,3-diacetyloxypropyl]-5-[3-acetyloxy-2-oxo-1-pyrrolidinyl]-2,4,6-triiodo-1,3-benzenedicarboxamide as an off-white foam (4.45 g, 71% yield).

Provenance & Evidence