tert‐Butoxide‐Mediated Synthesis of 3,4′‐Biquinolines from 2‐Aminochalcones

Abstract

A novel protocol to synthesize 3,4'biquinolines from 2-aminochalcones in the presence of a stoichiometric amount of sodium tert-butoxide as the nucleophilic promotor was developed. Conjugate addition of tert-butoxide to 2-aminochalcones provided the corresponding enolates, which underwent Michael addition to another molecule of 2aminochalcone to afford a dimeric species of 2aminochalcones. Subsequent cyclization between the amino and carbonyl groups followed by aromatization provides 3,4'-biquinoline products. Various 2-aminochalcones were submitted to this protocol and the desired 3,4'-biquinoline products were obtained in good to high yields in a short reaction time.Scheme 1. Nucleophile-Controlled Divergent Syntheses of Quinolines 2 and 3,4'-Biquinolines 3 from 2-Aminochalones 1.

NEW ROUTE FOR THE SYNTHESES OF SOME NOVEL DERIVATIVES OF 3-ARYL BENZO[d] THIAZOLE-2(3H)-IMINE FROM HIGH SUBSTITUTED THIOUREAS

“…At the first stage of the survey, we optimized the synthesis method of the compound from accessible reagents. Finally, target products were developed through reaction different types of synthesized N-acyl-N'-aryl thiourea derivatives with a diazonium salt in the presence of an excess of sodium tert-butoxide as a bulky strong non-nucleophilic base with moderate yield [36][37][38]. The results of this study and the details of the employed methodology are mentioned in the next sections.…”