An improved and benign synthesis of 9,10-diarylacridine-1,8-dione and indenoquinoline derivatives from 3-anilino-5,5-dimethylcyclohex-2-enones, benzaldehydes, and 1,3-dicarbonyl compounds in an ionic liquid medium

Improved and green syntheses of 9, 10-diarylacridine-1,8-dione and indenoquinoline derivatives were accomplished by the reactions of 3-anilino-5,5-dimethylcyclohex-2-enones, benzaldehydes, and 1,3-dicarbonyl compounds in the ionic liquid medium [bmim(+)][BF4-]. Not only the substituted anilines containing electron-donating groups, but also those with electron-withdrawing groups all gave excellent yields. Furthermore, the interesting unsymmetrical 9,10-diarylacridine-1,8-dione moiety with different groups in the 3- and 6-positions and indenoquinoline derivatives were obtained and are reported here for the first time in the literature. The Knoevenagel condensation and Michael addition intermediates were obtained successfully. A possible mechanism of the reaction is discussed in detail.