| 摘要 |
PURPOSE: A continuous process for preparing intermediate for non-ionic x-ray contrast agents is provided to reduce cycle times, the amount of equipment required in a production line, and headcount and to ensure consistent product quality in terms of yield, impurity profile and physical characteristics of the product. CONSTITUTION: A process for industrial preparation of 5-amino-N,N'-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophthalamide(Compound B) comprising the following sequential and continuous steps of: (i) iodinating 5-amino-N,N'-bis(2,3-dihydroxypropyl)-isophthalamide (ABA) or ABA-HCl using iodine chloride at a pH between about 2 and about 3 and at a temperature of between about 60 deg.C and about 90 deg.C in a first reactor; (ii) quenching the iodination reaction in a second reactor by adding a quenching reagent to a second reactor; (iii) decolourising the quenched reaction mixture in a third reactor at a pH above about 4 by adding a decolourising reagent; (iv) crystallizing the decolourised mixture by cooling to a temperature of about 25 deg.C and about 45 deg.C in a fourth reaction; and (v) filtering and washing the crystals of Compound B.
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