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Photosensitized Oxidation of Unsymmetrical
1,4-Dihydropyridines
H.R. Memarian*, M. Abdoli-Senejani and S. Tangestaninejad
Department of Chemistry, Faculty of Science, University of
Isfahan, 81746-73441 Isfahan, Iran
(Received 16 April 2006, Accepted 23 June 2006)
Photosensitized
oxidation of unsymmetrically substituted 1,4-dihydropyridines using dye
sensitizers methylene blue, rose bengal and tetraphenylporphyrin by taking
visible light source resulted in the aromatization of dihydropyridine ring
and formation of the corresponding pyridine derivatives. Comparison of the
results obtained under photosensitized reaction with those obtained by
direct photo-oxidation indicated a very fast and smooth reaction of these
compounds and formation of pyridine derivatives using theses dyestuffs.
Keywords:
1,4-Dihydropyridines, Photochemistry, Photooxidation, Photosensitized
oxidation, Singlet oxygen |
