Ammonia → HCID 12953246, compound

Participants

Reaction Steps

14 g of sodium nitrite is introduced under stirring into 170 ml of a concentrated sulfuric acid held at +5° C. The mixture is then maintained at +70° C. until solution has occurred, and then cooled to +5° C. After adding dropwise 84 ml of glacial acetic acid under cooling, 93.6 g of 5-amino-3-acetylaminomethyl-2,4,6-triiodobenzoic acid is added in incremental portions, maintaining the reaction temperature between 0° C. and +5° C. The reaction mixture is stirred for another 2 hours, poured on 800 g of ice, and, under cooling, introduced into a solution of 71 g of copper(I) cyanide and 133 g of potassium cyanide in a mixture of 1 1 of concentrated ammonia and 640 ml of water. After several hours of stirring in an ice bath, the precipitated ammonium salt is vacuum-filtered and dissolved in 4 l of water. After filtration over active carbon, the filtrate is adjusted to pH 6 with acetic acid, again extracted with active carbon, filtered, and the filtrate combined with excess concentrated hydrochloric acid. The thus-separated precipitate is dried at 50° C., thus obtaining 80.5 g (=85% theory) of 5-cyano-3-acetylaminomethyl-2,4,6-triiodobenzoic acid as a white powder, mp 271° C. (decomposition).

Provenance & Evidence