Diethyl (2-bromoethyl)phosphonate → Diethyl 2-(3,5-Bis-acetylamino-2,4,6-triiodobenzovloxy)ethylphosphonate

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Reaction Steps

To a stirred solution of sodium diatrizoate (7.1 g, 11.2 mmol) in dry dimethylformamide (50 ml) at room temperature under a blanket of argon was added a solution of diethyl 2-bromoethylphosphonate (3.02 g, 12.3 mmol, 1.1 eq.) in dimethylformamide (10 ml). After stirring for 12 hours, the solvent was evaporated under vacuum to give a white solid that was washed with 300 ml of saturated aqueous NaHCO3, and then extracted with a 2:1 mixture of chloroform-ethanol (3×200 ml). The organic extract was dried (MgSO4), filtered, and evaporated under vacuum to give 3.61 g (41%) of product as a white solid. Recrystallization from acetonitrile gave analytically pure material; mp 249-251° C.; MH+ (779). The 1H-NMR (300 MHz) spectrum was consistent with the desired material.

Provenance & Evidence