碘他拉酸的合成

Synthesis of Iothalamic Acid

5-硝基-1,3-苯二甲酸单甲酯和40%甲胺水溶液经酰胺化反应得到3-硝基-5-[(甲胺基)羰基]苯甲酸,再经Pd/C催化氢化还原和氯化碘碘代得到3-氨基-2,4,6-三碘-5-[(甲胺基)羰基]苯甲酸,最后经乙酰化反应制得离子型X线造影剂碘他拉酸,总收率约80%。

Iothalamic acid, an ionic X-ray contrast agent was synthesized from monomethyl 5-nitroisophthlate and methylamine by amidation to give 3-nitro-5- E （methylamino） carbonyl] benzoic acid, which was subjected to catalytic hydrogenation and iodination to afford 3-amino-2,4,6-triiodo-5-[ （methylamino）carbonyl] benzoic acid, followed by acetylation with acetic anhydride with an overall yield of about 80 %.