No abstract

No abstract

No abstract

In Dimethylsulfoxid wird aus 2‐Fluor‐naphthalin (I) und tert. ‐Butylat (II) der tert. ‐Butyläther (III) hergestellt.

SUMMhRYThe reaction of 1251 with 3,S-diiodo-L-thyronine (T2), 3,3',5triiodo-L-thyronine (T3), and L-thyroxine (Tq) have been studied under various pH and concentration conditions. when t h e pH is 7.5 and approximately e q u h l a r amounts of thyronine substrate and 1251 a r e reacted, T2 produces a s t h e major product monolabeled T3 of high specific a c t i v i t y ( m 3 3 0 0 mCi/mg) and long term s t a b i l i t y while T produces a s the major product approximately 30% dilabeled 1 2 5 1~4 with short term s t a b i l i t y and a specific a c t i v i t y of -3000 mCi/mg. Simple methods f o r purification of t h i s product t o make it useful a r e discussed. 8.7 and the molar ratio of 1251 t o thyronine substrate is increased t o 1:6 then T produces a s the major product T 3 3 a c t i v i t y (-500 mCi/mg) and long term s t a b i l i t y while T4 produces very stable monolabeled T4 of medium specific a c t i v i t y (-250 mCi/mg).The mechanisms of substitution and exchange, a s they r e l a t e t o the formation of these and other side products i n these reactions, are discussed.It was found t h a t 3 When the px is raised t o of medium specific