Prepn. of 5-amino- 2,4,6-tri:iodo-1,3-benzene di:carboxylic acid - by catalytic hydrogenation of 5-nitro-1,3-benzene di:carboxylic acid and iodination of the product

摘要

Prepn. of 5-amino-2,4,6-triiodo-1,3-benzene dicarboxylic acid comprises: (a) catalytic hydrogenation of 5-nitro-1,3-benzene dicarboxylic acid in neutral or basic conditions to give an aq. soln. of 5-amino-1,3-benzene dicarboxylic acid Na sa (b) direct iodination of the product soln., without further purification, with a soln. of ICl in HCl, where the 5-amino-1,3-benzene dicarboxylic acid Na salt soln. has previously had HCl and H2SO4 added to it.