*4.2. General Information*

Melting points (mp) (in ◦C), were determined on a Boëtius hot plate microscope (VEB Wägetechnik Rapido, PHMK 81/3026, Radebeul, Germany) and are reported uncorrected. UV/VIS spectra were recorded for solutions of the new compounds in methanol at concentration of ≈0.025 mM and in acetonitrile at ≈0.015 mM on an Analytik Jena Specord 40 ultraviolet/visible spectrophotometer (Analytik Jena AG, Jena, Germany) using a quartz cuvette with a path length of 1.00 cm. Values of the wavelength (corresponding to the maximum absorbance), *λ*max (in nm), and of the logarithm to the base 10 of the molar absorption coefficient, *ε*max (M−<sup>1</sup> · cm<sup>−</sup>1) are provided. FTIR spectra were collected with a Bruker Optics Vertex 70 Fourier-transform infrared spectrophotometer (Bruker Optics GmbH, Ettlingen, Germany) using the conventional KBr pellet technique. The position of the selected absorption bands in the FTIR spectra is reported using the wavenumber at the absorption maximum, *<sup>ν</sup>*max (in cm<sup>−</sup>1). The intensity of the FTIR peaks is provided as very strong (vs); strong (s); medium (m); and weak (w). Nuclear magnetic resonance spectra were registered on a Varian Gemini 300 BB NMR spectrometer (Varian, Inc., Palo Alto, CA, USA) operating at 300 MHz for 1H NMR and 75 MHz for 13C NMR, in deuterated solvents, i.e., dimethyl sulfoxide-*d*<sup>6</sup> (DMSO-*d*6) or deuterochloroform (CDCl3). Additional evidence was provided by the 2D HETCOR and COSY experiments. Chemical shifts, *δ*, were measured in ppm with respect to the 1H or 13C resonance of (CH3)4Si (tetramethylsilane, TMS), and the coupling constants, *J*, are expressed in Hz. The multiplicity of 1H NMR signals is provided as per the following convention: singlet (s); doublet (d); doublet of doublets (dd); triplet (t); triplet of triplets (tt); septet (sept); septet of doublets (septd); octet (oct); multiplet (m); and broad (br). Proton NMR spectroscopic data are quoted in the following order: 1H chemical shift, multiplicity, proton number, signal/hydrogen atom assignment, coupling constants, and 13C NMR spectroscopic data are reported as follows: *δ*C-value, signal/carbon atom attribution. GC/EI–MS data were acquired on a Fisons Instruments GC 8000 series gas chromatograph coupled to an MD 800 mass spectrometer detector equipped with an electron ionization source and with a quadrupole mass analyzer (Fisons Instruments SpA, Rodano, Milano, Italy), using an SLB-5ms capillary column (df 0.25 μm; L × I.D. 30 m × 0.32 mm), CH2Cl2 as solvent, and a flow rate of helium carrier gas of 2 mL/min. Reversed-phase high-performance liquid chromatography (HPLC) was performed on a Beckman Coulter System Gold 126 liquid chromatograph, equipped with a

System Gold 166 UV/VIS spectrophotometer detector (Beckman Coulter, Inc., Fullerton, CA, USA), a Rheodyne injection system, and a LiChrosorb RP-18 column (dp 5 μm; L × I.D. 25 cm × 4.6 mm). The flow rate of eluent, a mixture of CH3OH–H2O in different volume ratios, was 1 mL/min. The compounds' purities (%) and retention times, *t*<sup>R</sup> (in min), were reported. Elemental analysis was carried out on a Costech ECS 4010 instrument (Costech Analytical Technologies Inc., Valencia, CA, USA).
