摘要:
The reactions of 4,6-dinitro-1-phenyl-1H-indazole with anionic nucleophiles RS- and N-3(-) lead to the regiospecific replacement of the nitro group at position 4. The reaction with N2H4 . H2O + FeCl3 also results in reduction of only the 4-NO2 group. Based on this fact, a procedure was developed for the preparation of previously unknown 3-unsubstituted 4-X-6-nitro-1-phenyl-1H-indazoles (X is a residue of a nucleophile or NH2). Comparison of the data on the selective nucleophilic substitution (4-NO2 group) in 3-Z-1-aryl-4,6-dinitro-1H-indazoles shows that in the case of Z = H, the regiospecificity of substitution is determined by the electronic effect of the annelated pyrazole ring.