A modified approach to C??14??labeled 2??(3, 4??difluorophenoxy)??5??fluoronicotinic acid and other halogen??substituted analogs

Y Zhang, Z Jian, WT Stolle

Index: Zhang, Yinsheng; Jian, Zhigang; Stolle, Wayne T. Journal of Labelled Compounds and Radiopharmaceuticals, 2011 , vol. 54, # 7 p. 382 - 386

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Abstract

Abstract A modified approach to a carbon-14-labeled pyridine ring system was developed based on the electrocyclic ring-closure of 1, 4, 4-trisubstituted butadiene. The new method was applied to prepare 2-(3, 4-difluorophenoxy)-5-fluoro-[2-14 C] nicotinic acid and other halogen-substituted analogs. The targeted compound was isolated with a radiochemical purity of> 98% and a specific activity of 53 mCi/mmol from four radiochemical steps, ...