3-acetyl coumarins on condensation with various aromatic aldehydes in the presence of piperidine gave corresponding chalcones in a solid state under solvent free conditions. These chalcones are isolated and characterized. The in-situ-formed chalcones (1) are also converted into corresponding 2-aryl-4-[2H-2-oxo[1]benzopyran-3-yl]-2,3-dihydro (3) and 2,5-dihydro-1,5-benzothiazepines (4) in one step by interacting with orthoamino thiophenol. Both the 2,3-dihydro (3) and 2,5-dihydrobenzothiazepines (4) have been converted into same tetrahydrobenzothiazepine (5). Finally, the tetrahydrobenzo thiazepine (5) is converted into its acetyl derivative (11). The structures of the title compounds have been confirmed on the basis of their microanalytical, IR, 1 H NMR, and mass spectral data.
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Acknowledgments
The authors are grateful to the Director, IICT, Hyderabad, and CDRI, Lucknow, for providing spectral data.
Notes
*All compounds were recrystallized from methanol.
*All compounds were recrystallized from methanol.
*All compounds were recrystallized from methanol.