Synthesis of Tricyclic Quinoline Derivatives from 5- and 6- Aminoindazoles and 5-Aminoindole under Conventional Way and Microwave System

Abstract

Targeted tricyclic quinolines were prepared from the corresponding aminoindazolic and indolicderivatives as starting materials using two comparative methods; conventional heating and microwaveirradiation. We noticed that the syntheses of 5-amino-1-methylindazole and 5-aminoindole wereabandoned due to their conversion to fluorescent products one week after free contact with air andacetone. As a result of this finding, we decided to condense the relevant amine with acetone or mesityloxide to confirm our hypothesis. We show that the amine is converted to the derived quinoline throughthese condensation processes. Subsequently, this reaction was extended to the aminoindazolederivatives of positions 5 and 6, yielding the appropriate quinoline derivatives. Similarly, 5-aminoindoleexhibited the same reactivity. By applying the corresponding NMR and centesimal techniques, theresulting structures were identified.