111753-15-2Relevant articles and documents
peri-Substituted Imidazopyridines. A New Reductive Elimination Reaction
Rees, Charles W.,Smith, David I.
, p. 1159 - 1164 (2007/10/02)
A new reductive elimination reaction of 3,5-disubstituted imidazopyridines (3) with hydrazine is reported.Thus on treatment of the 3,5-dibromo (7a), 5-bromo-3-nitro (7b), and 3,5-dinitro (4) derivatives with hydrazine hydrate in hot ethanol, the bromine and nitro groups are replaced by hydrogen.A mechanism based on the conjugated relationship of these peri-substituents is proposed and used to explain the reported conversion of 1,3,5-trichloro-2,4,6-trinitrobenzene (9) into 1,3-dichloro-4,6-dinitrobenzene (10).A variety of other 3-nitro-5-substituted imidazopyridines (15)-(18) is described, but these could not be cyclised to 1,2,4-triazacyclopentindenes.The 3-amino-5-methoxycarbonyl derivative (19a) cyclises to the triazacyclopentindenone (20) with sodium methoxide.