碘比醇中间体的合成

Synthesis of intermediates of iobitridol

研究了碘比醇两种中间体的合成.以丙二酸二乙酯为原料,经过羟甲基化、二羟基保护、皂化、酸化、脱羧再酸化得到中间体2-异丙基-5-羧基-1,3-二氧六环,总产率47.5%,最终产物经元素分析1、H NMR谱确证.另外还尝试了中间体2,2-二甲基-5-羧基-1,3-二氧六环的合成,通过核磁共振图谱发现在不同的酸度进行酸化时,前体2,2-二甲基-5,5-二羧基-1,3-二氧六环均有不同程度的分解.

The synthesis of two intermediates of iobitridol has been studied. 2-Isopropyl-5-carboxy-1,3-dioxane was prepared using diethyl malonate as starting material with a total yield of 47. 5%, through a series of reactions of hydroxymethylation, dihydroxy-protection, saponification, acidification, decarboxylation. In addition, an attempt to prepare 2, 2-dimethyl-5-carboxy-1,3-dioxane was also made. ^1H NMR spectrum showed that 2,2-dimethyl-5,5-dicarboxy-1,3-dioxane hydrolyzed in differently acidy solution. The final product was confirmed by elemental analysis and ^1 H NMR.