The 1 H spectra were recorded at room temperature on a Bruker Advance 300 spectrometer (Bruker, USA). Coupling constants were measured in Hertz (Hz) and multiplicities for 1 H NMR coupling were presented as s (singlet), d (doublet), t (triplet), q (quintuplet), h (hexuplet) and m (multiplet). Chemical shifts are reported relative to the sodium trimethylsilylpropionate reference.