Electrophilic substitution in N-aryl-2-pyrazolines. 4. Azo coupling reactions

Abstract

Phenyldiazonium chlorides enter into the azo coupling reaction with 2pyrazoline derivatives at the para position of the N-aromatic nucleus. The reaction is very sensitive to sterlc and electronic effects of the substituting groups in the pyrazolines.The electronic spectra and acld-base properties of the synthesized azopyrazolines are discussed.

Synthesis of chlorinated 3,5-diaryl-2-pyrazolines by the reaction of chlorochalcones with hydrazines

“…Although several chlorinated 2-pyrazolines have already been prepared, 15,17,21,27,28,33 these compounds were individual members of variously substituted 2-pyrazoline series. For this reason, our aim was to synthesize 1-substituted 3,5-diaryl-2-pyrazolines, chlorinated in their aromatic rings connected to the C-3 and C-5 atoms of the pyrazoline skeleton, by the reaction of chlorochalcones with hydrazines.…”