153953-01-6Relevant articles and documents
Process for the preparation of imidazopyridines
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, (2008/06/13)
The invention relates to a novel process for the preparation of imidazopyridines of formula I: STR1 in which R is an alkyl having 1-6 C atoms, characterized in that 3,4-diamino-2-chloropyridine (II) is reacted with an acid anhydride of the formula RCO--O--COR 40 (III), in which R is as defined and R' is R or can be another aliphatic or aromatic radical, to give a 4-amino-2-chloro-3-R-CO-aminopyridine (IV), this is converted with 4'-bromomethyl-2-cyanobiphenyl (V), in the presence of an alkali metal alcoholate in an inert solvent, to a 4-amino-2-chloro-3-R-CO-[N-(2'-cyano-biphenyl-4-ylmethyl)-amino]pyridine (VI) and this is treated with a strong acid, a 2-R-4-chloro-3-(2'-cyano-biphenyl-4-ylmethyl)-3H-imidazo[4,5-c]pyridine (VII) being formed as an intermediate.