32
M. Cetina et al. / Journal of Molecular Structure 969 (2010) 25–32
singlets at 4.58 and 4.43 ppm are attributed to two methylene pro-
tons of –CH2–O–CH3 group for all the compounds, respectively.
For compounds 1 and 2 the 1H NMR spectra exhibit a deuterium
oxide exchangeable broad singlet corresponding to OH or NH pro-
tons in the region 13.27–12.49 ppm, and for compounds 1 and 3 a
signal in the range of 6.28–6.42 is assigned to the H-5 proton.
Appendix A. Supplementary data
Supplementary data associated with this article can be found, in
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Support for this study by the Ministry of Science and Technol-
ogy of Croatia (project No. 058-2261-2253 and 119-1193079-
3069) is gratefully acknowledged.
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