Popis: |
Microwave (MW) irradiation activated the reaction of dimedone with aniline or p-chloroaniline in formic acid to give the acridine derivatives 2a and 2 b, respectively, which can be derivatized as the bisoximes 3 and bisphenylhydrazone 4. However, under the same reaction conditions 2- aminopyridine gave the xanthene derivative 6 and not the expected acridine derivative 2c. When 2-aminopyridine was allowed to react under MW irradiation with dimedone in presence of benzaldehyde in ethanol it gave the bis(dimedonyl)methane derivative 10. Cyclization of 10 has been enhanced under MW irradiation to give the xanthene derivative 9 in improved yield and in less time than the conventional heating. The structures of products were confirmed from the analysis of their IR, 1 H-NMR and mass spectra. The antimicrobial activity has been investigated for compounds 3, 4, 6 and 10. |