3939-15-9Relevant academic research and scientific papers
Syntheses of dual-radioisotope-labeled CP-I, a GABAA receptor partial agonist
Zhang, Yinsheng,Greenfield, Laura,Hong, Yang
scheme or table, p. 411 - 417 (2012/07/13)
CP-I is a potent subtype-selective GABAA receptor partial agonist. Owing to its significant metabolic cleavage at C8 observed in preliminary biotransformation studies with non-radiolabeled CP-I, the syntheses of CP-I labeled at the right or left hand side with 14C or labeled with 3H at the right hand side were required. The two compounds labeled with 14C at the left or right hand side were synthesized in 2 and 5 radio-synthetic steps using [14C]2-chloroacetyl chloride and [ 14C]NaCN as starting radiolabeled materials, respectively. CP-I was labeled with tritium at the right hand side by a tritium de-halogenation method. Batches of radiolabeled CP-I were mixed to give dual-radioisotope-labeled CP-I. An efficient approach to [14C]fluoropyridinyl imidazole was developed, and a short synthesis of iodo-substituted fluoropyridinyl imidazole was also achieved. The details of these syntheses are discussed. Copyright
Preparation of 2-Fluoropyridines via Base-Induced Decomposition of N-Fluoropyridinium Salts
Umemoto, Teruo,Tomizawa, Ginjiro
, p. 1726 - 1731 (2007/10/02)
N-Fluoropyridinium salts with either BF4-, SbF6-, or PF6- as a counteranion were treated with excess base such as triethylamine at room temperature to give 2-fluoropyridine in good yield.This method was succesfully applied to the preparation of 2-fluoropyridine derivatives possessing electron-donating or -withdrawing substituents using substituted N-fluoropyridinium tetrafluoroborates.Pyridine-F2 compounds produced through reactions of pyridines with molecular fluorine were also treated with base to give 2-fluoropyridines but in low yields.These reactions are considered to occur through a carbene mechanism as follows: a novel N-F-containing cyclic carbene (3), generated from the N-fluoropyridinium salts by 2-proton abstraction, reacts with fluorine atoms from counteranions such as BF4-, SbF6-, or PF6-, followed by elimination of F- from the N-F moiety, to yield 2-fluoropyridines.Previously reported findings in reactions of pyridines with molecular fluorine are explained on the basis of this mechanism.
