医药中间体5-氨基-2,4,6-三碘异酞酸的制备

Synthesis of Medical Intermediate 5-Amino-2,4,6-triiodoisophthalic Acid

以间苯二甲酸为原料 ,经硝化、还原与碘化 ,合成非离子含碘造影剂的中间体 5 氨基 2 ,4,6 三碘异酞酸。 (1)硝化反应 ,n(硫酸 )∶n(硝酸钠 )∶n(间苯二甲酸 ) =7 9∶2 2∶1 0 ,温度 70℃下反应 3h ,产率为 86 7% ;(2 )还原反应 ,n(铁粉 )∶n(硝基物 ) =3 0∶1 0 ,回流反应 3h ,产率为78 1% ;(3)碘化反应 ,n(氯化碘 )∶n(氨基物 ) =3 3∶1 0 ,90℃下反应 3h ,碘化反应产率为76 2 %。每步均经改进 ,总收率为 5 1 6 % ,所得产品熔点、UV、IR、1HNMR。

The synthesis of 5 amino 2,4,6 triiodoisophthalic acid,which is used as intermediate for nonionic iodinated X ray contrast agents,is described in this paper.5 Amino 2,4,6 triiodoisophthalic acid was synthesized from isophthalic acid by a three step procedure,nitration,reduction and iodination.(1)Nitration:at n (sulfuric acid)∶ n (sodium nitrate)∶ n (isophthalic acid)=7 9∶2 2∶1 0 after reacting at 60 ℃ for 3 h,the yield of nitro compound was 86.7%.(2)Reduction:at n (iron)∶ n (nitro compound)=3.0∶1 0 after refluxing for 3 h,the yield of amino compound was 78.1%.(3)Iodination:at n (ICl)∶ n (amino compound)=3 3∶1 0 after heating at 90 ℃ for 3 h,the yield of iodination product was 76 2%.The overall yield was 51 6%.Melting point and UV,IR, 1HNMR and 13 CNMR spectra of the prepared product were identical with those reported in the literatures.