The labeling of 4‐alkylamino‐iodoquinolines with radioactive iodine by isotopic exchange

Abstract

SUMMARY:4-alkylamino-iodoquinolines can be labeled as their phosphate salts in high yields and in a short period of time by nucleophilic exchange in a melt with radioactive iodide. The iodide must be free of NaCl and reducing agents.

No-Carrier-Added Radiohalogenation Methods with Heavy Halogens

“…The isotopie exchange in various aromatic radiopharmaceuticals [68 -80] has been achieved in a melt [68,[70][71][72][73] or a concentrated solution of acetic acid [69], propylene glycol [75,76], or water [77] at elevated temperatures (100-170°C). By aromatic isotopie exchange, 50 to 90% yields and specific activities of 2 to 3 mCi/mmole were obtained [68, 78 -80], which were sufficient for animal distribution studies [81][82][83].…”

Radioiodination techniques for small organic molecules

“…This is substantiated by the observation that sulfuric acid can be successfully substituted for ammonium sulfate to promote the exchange.194,196 A series of iodobenzylguanidines, the three iodobenzoic acids, and other iodo aromatics have been radioiodinated by the ammonium sulfate method.196 A related finding is that the iodine exchange of a series of 4-(alkylamino)iodoquinolines is greatly facilitated by the use of their phosphate salts. 196 As the pH went down, the radiochemical yields went up.…”