Manufacturing Process

3,5-Dinitrobenzoic acid (15.9 g) was dissolved in an equivalent amount of sodium hydroxide solution, and the solution was diluted to 310 ml with water. The solution was refluxed with Raney nickel for fifteen minutes, filtered, and the filtrate was hydrogenated at elevated pressure using platinum oxide catalyst. After the amount of hydrogen calculated to reduce both nitro groups had been absorbed, the mixture was filtered, and the filtrate was acidified with an equal volume of concentrated hydrochloric acid. Iodine monochloride (17 ml) in 100 ml of 6N HCl was then added with stirring. The reaction mixture was allowed to stand for two and one-half hours at room temperature, then diluted with an equal amount of water with vigorous stirring, and the solid material was collected by filtration and recrystallizedfrom dilute methanol, giving 18.5 g of 3,5-diamino-2,4,6-triiodobenzoic acid, MP about 135°C with decomposition. The 18.5 g of 3,5-diamino-2,4,6- triiodobenzoic acid was suspended in 150 ml of acetic anhydride containing 5 drops of 70% perchloric acid, and the mixture was heated on a steam bath for three and one-half hours. The reaction mixture was poured into 300 ml of ice water, and then heated on a steam bath until crystallization took place. The solid material was collected by filtration, dissolvedin dilute sodium hydroxide solution, filtered, and hydrochloric acid was added to the filtrate to reprecipitate the acid product. The latter was again dissolved in sodium hydroxide and reprecipitated with acid, giving 9 g of 3,5-diacetamido-2,4,6- triiodobenzoic acid, MP above 250°C.The acid may be used as the sodium salt or as the meglumate.

Therapeutic Function

Diagnostic aid (radiopaque medium)

Definition

ChEBI: A member of the class of benzoic acids that is benzoic acid having iodo substituents at the 2-, 4- and 6-positions and acetamido substituents at the 3- and 5-positions. It is used, mainly as its N-methylglucamine and sodium salts, as an -ray contrast medium in gastrointestinal studies, angiography, and urography.

Brand name

Md (Mallinckrodt); Urovist Sodium (Berlex).

General Description

Diatrizoate is a water-soluble, ionicmonomer. It is commercially available as the megluminesalt, sodium salt, or as fixed combinations of the two saltforms. These triiodobenzoic acid salts contain 47% organicallybound iodine.Numerous products with various concentrations of one ortwo of the salt forms are available for various imaging procedures.Indicated uses include angiography, venography,excretory urography, retrograde cystourethrography, retrogradeor ascending pyelography, operative, T-tube, or percutaneoustranshepatic cholangiography, splenoportography,arthrography; discography, radiographic examinationof the GI tract when barium sulfate is contraindicated (i.e.,suspected perforation of the GI tract), adjunct contrast enhancementin CT of the torso (dual contrast study), and hysterosalpingography.