| abstract |
The present invention relates to a novel process for preparing iopromide which is used as a contrast agent for X-ray, wherein 5-methoxyacetylamino-2,4,6-triiodoisophthalic acid (2,3-diacetoxypropyl)amide chloride of formula (19) and 5-methoxyacetylamino-2,4,6-triiodoisophthalic acid [(2,3-dihydroxy-N-methylpropyl)-(2,3-diacetoxypropyl)]diamide of formula (20) are introduced as intermediates, by which a bismer by-product generated during the preparation process can be removed even without an additional removal procedure and thus iopromide with high purity can be prepared in high yield. |