N-Fluoro derivatives of nitrated pyrazole-containing fused heterocycles
摘要:
N-Fluorination of Na-salts of polynitrated bipyrazoles and pyrazole-based fused heterocycles with fluorine-nitrogen mixture (10% F-2) at -60 to -70 degrees C in MeOH in the presence of NaF occurs regiospecifically at the nitrogen atom most distant from nitro groups.
Unsubstituted 1H,7H-dipyrazolo[3,4-b-,4',3'-e]pyrazine has been synthesized for the first time starting from 5-amino-3-methyl-1-phenylpyrazole. Its nitration to form C- and N-dinitro-substituted derivatives has been studied. The molecular structure of 3,5-dinitro-1H,7H-dipyrazolo[3,4-b;4',3'-e]pyrazine has been established by X-ray structural investigation; the NH acidity of this compound and the orientation of its alkylation with bromoacetone have also been determined.