S-(-)-5-2-(Acetyl-oxy)-1-oxo-propyl amino-2,4,6-tri:iodo-1,3-benzene di:carboxylic acid di:chloride prepn. - comprises reacting S-(-)-2-(acetyl-oxy)propionic acid chloride and 5-amino-2,4,6-tri:iodo-1,3-benzene di:carboxylic acid di:chloride in presence of halo-hydric acid

摘要

Prepn. of S-(-)-5-[[2-(acetyloxy)-1-oxopropyl]amino]-2,4,6-triiodo-1,3-benzene dicarboxylic acid dichloride (I) comprises; (a) catalytic hydrogenation of 5-nitro-1,3-benzene dicarboxylic acid in neutral or basic environment to give and aq. soln. of 5-amino-1,3-benzene dicarboxylic acid sodium salt (IV); (b) addn., without further purificn., of a soln. of ICl in HCl to a soln. of (IV) in HCl and H2SO4 to give 5-amino-2,4,6-triiodo-1,3-benzene dicarboxylic acid (V); (c) reaction of (V) and thionyl chloride in heterogeneous phase, in a solvent selected from 7-16C hydrocarbons, 7-8C aromatic hydrocarbons, 1,1,1-trichloroethane, n-butyl acetate or diglyme (diethyleneglycoldimethylether), in the presence of a catalytic amt. of tert. amine to give 5-amino-2,4,6-triiodo-1,3-benzene dicarboxylic acid dichloride (III); and (d) reaction of (III) and S-(-)-[2-(acetyloxy)]propionic acid chloride (II) in an aprotic dipolar solvent in the presence of a halohydric acid.