- DIHYDROPYRIMIDINE DERIVATIVES AND USES THEREOF IN THE TREATMENT OF HBV INFECTION OR OF HBV-INDUCED DISEASES
-
The application describes dihydropyrimidine derivatives which are useful in the treatment or prevention of HBV infection or of HBV-induced diseases, more particularly of HBV chronic infection or of diseases induced by HBV chronic infection, as well as pharmaceutical or medical applications thereof.
- -
-
Page/Page column 39; 248
(2020/01/24)
-
- Preparation of 2-Fluoropyridines via Base-Induced Decomposition of N-Fluoropyridinium Salts
-
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.
- Umemoto, Teruo,Tomizawa, Ginjiro
-
p. 1726 - 1731
(2007/10/02)
-
- DIRECT FLUORINATION OF SUBSTITUTED PYRIDINES
-
The direct fluorination of pyridines bearing alkyl, halogen, ester, or ketone functions has been employed to prepare the corresponding 2-fluoro-substituted pyridines.
- Puy, Michael Van Der
-
p. 255 - 258
(2007/10/02)
-