Synthesis of chalcone analogs and derivatives of 2-pyrazoline from 3-formylindole

By the crotonic condensation in an alkaline medium of 3-formylindole with various aromatic and heterocyclic methyl ketones, and also with cyclopentanone, cyclohexanone, and 1,4-diacetylbenzene, we have synthesized nineteen ,-unsaturated ketones. The majority of them were characterized as the 2,4-dinitrophenylhydrazones, the absorption maxima of which in chloroform are given. Some considerations are expressed concerning the reactivity of 3-formyl- and 3-acetylindoles. Ten 3-aryl-1-phenyl-5-(indol-3-yl)-2-pyrazolines and their analogs with a 3-heterocyclic residue have been synthesized by the reaction of 3-aryl-1-(indol-3-yl)propen-3-ones and the corresponding analogs with phenylhydrazine. Some of the compounds synthesized possess a bright luminescence.