Background: Thiosemicarbazones containing mono- or disaccharide moieties reveal several
various remarkable biological activities; therefore these compounds have been focused in organic
syntheses. Sydnone ring is the potential basic pharmacodynamic nucleus, which has been reported to
possess a wide variety of biological activities such as antitumor, anticancer, anti-inflammatory, antiviral,
and scavenging activities. The connection of monosaccharide moiety to sydnone ring could initiate
the new activities.
Methods: The synthetic reaction of different substituted 3-phenyl-4-formylsydnone N-(tetra-O-acetyl-β-
D-galactopyranosyl)thiosemicarbazones was carried out under microwave-assisted heating conditions.
The structures of obtained thiosemicarbazones were confirmed by IR, NMR and mass spectra. All obtained
thiosemicarbazones were screened for DPPH radical scavenging ability.
Results: Some different substituted 3-formyl-4-phenylsydnones were prepared by Vilsmeier-Haackʹs
formylation reaction. These substituted 4-formylsydnones were converted into corresponding thiosemicarbazones
by condensation with N-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)thiosemicarbazide. Some of
these thiosemicarbazones showed remarkable DPPH radical scavenging ability.
Conclusion: The efficient synthesis of 3-phenyl-4-formylsydnone N-(tetra-O-acetyl-β-D-galactopyranosyl)
thiosemicarbazones under microwave-assisted refluxing conditions has been reported. Reaction yields
were 40-80%. Obtained results showed that the compounds 4f and 4g have high antioxidant activity.