## 2 Materials and Methods  
### Chemistry  
The reagents and solvents that were used in this research were purchased from Sigma-Aldrich Co. (Saint Louis, MI, USA), Merck Co. (Darmstadt, Germany) and Polish Chemical Reagents POCh (Gliwice, Poland). These chemicals were used without further purification. Microwave-assisted synthesis of hydrazide-hydrazones was performed with the use of the CEM Discover system 908010 synthesizer (CEM Co., Matthews, NC, USA). Thin-layer chromatography (TLC) was applied to check the purity of synthesized hydrazide-hydrazones and to monitor the progress of performed reactions. Aluminum plates were covered with silica gel (aluminum oxide 60 F-254, Merck Co., Darmstadt, Germany), and chloroform-ethanol mixture 10:1 (\(v/v\)) was used as a mobile phase. Irradiation with UV light (\(\lambda=254\) nm) was used to detect the spots on the chromatograms. The Nicolet 6700 FT-IR spectrophotometer (Thermo Scientific, Waltham, MA, USA) in the ATR mode was used to register the IR spectra of synthesized acylhydrazones. The \({}^{1}\)H NMR and \({}^{13}\)C NMR spectra were registered with the Bruker Avance 300 and 600 apparatus (Bruker BioSpin GmbH, Ettlingen, Germany). The melting points of obtained compounds were measured with the use of the Fisher-Johns apparatus (Fisher Scientific, Hampton, NH, USA). An elemental analysis of synthesized compounds was performed with the use of a Perkin Elmer 2400 series II CHNS/O analyzer (Waltham, MA, USA). Detailed Procedure for the Synthesis of Hydrazide-Hydrazones of Phenylacetic Acid **(2-16)**  
An amount of 0.001 mole of hydrazide of phenylacetic acid **(1)** was placed in a tube appropriate for microwave synthesis and dissolved in 4 mL of ethanol (96%). Subsequently, 0.0011 mole of appropriate substituted aromatic aldehyde was added, and the content of the tube was subjected to microwave radiation (300 W of power, for 7 min at 155 \({}^{\circ}\)C). After that, the precipitate was filtered off under reduced pressure and dried. In the case of compounds **9**, **10**, **11** and **16**, the precipitate appeared after 24 h. The obtained compounds were re-crystalized from ethanol (96%) (Scheme 1). \begin{tabular}{|c|c|c|c|} \hline
**Compound** & **R** & **Compound** & **R** \\
**Number** & & **Number** & **R** \\ \hline
**2** & 5-Br-2-OH & **10** & 3-OCH-2-OH-5-I \\ \hline
**3** & 3,5-diBr-2-OH & **11** & 3-OCH-5-2-OH \\ \hline
**4** & 5-Cl-2-OH & **12** & 2-OH-3-NOi \\ \hline
**5** & 3,5-diCl-2-OH & **13** & 2-OH-5-NOi \\ \hline
**6** & 3-Br-5-Cl-2-OH & **14** & 4-OH-3-NOi \\ \hline
**7** & 5-Cl-2-OH-3-I & **15** & 2-OH-3-5-diNOi \\ \hline
**8** & 2-OH-3-5-dil- & **16** & 2,3,4-triOH \\ \hline
**9** & 2-Br-3-OH-4-OCHi & & \\ \hline \end{tabular}   
**Scheme 1. ** Synthesis of acylhydrazones of phenylacetic acid. \(N^{\prime}\)-[(_E_)-(5-bromo-2-hydroxyyphenyl)methylidene]-2-phenylacetohydrazide (**2**)  
Color: light yellow; M.p. : 198-200 \({}^{\circ}\)C; yield: 85%; for C\({}_{15}\)H\({}_{13}\)BrN\({}_{2}\)O\({}_{2}\) (333.18) calculated: C: 54.07%, H: 3.93%, N: 8.41%; found: C: 54.21%, H: 3.91%, N: 8.44%. IR (cm\({}^{-1}\)); 3186 (NH), 3064 (CH, arom. ), 2950, 2907 (CH, aliph. ), 1662 (C=O), 1603 (C=N); \({}^{1}\)H NMR (600 MHz, DMSO-\(d_{6}\)): 3.57 (s, 2H, CH\({}_{2}\)), 6.87 (t, 2H, ArH, \(J\) = 6 Hz), 7.22-7.28 (m, 1H, ArH), 7.29-7.34 (m, 1H, ArH), 7.37-7.42 (m, 1H, ArH), 7.75 (d, 1H, ArH, \(J\) = 6 Hz), 7.81 (d, 1H, ArH), 8.38 (s, 1H, =CH), 11.43 (s, 1H, OH), 11.93 (s, 1H, NH); \({}^{13}\)C NMR (150 MHz, DMSO-\(d_{6}\)): 41.44 (CH\({}_{2}\)), 110.86, 119.08, 127.15, 128.83, 129.57, 133.95, 135.84, 138.93 (10\({}_{\rm{Car}}\)), 144.99 (=CH), 155.95, 156.77 (2C\({}_{\rm{ar}}\)), 167.04 (C=O). \(N^{\prime}\)-[(_E_)-(3,5-dibromo-2-hydroxyphenyl)methylidene]-2-phenylacetohydrazide (**3**)  
Color: light yellow; M.p. : 222-226 \({}^{\circ}\)C; yield: 95%; for C\({}_{15}\)H\({}_{12}\)Br\({}_{2}\)N\({}_{2}\)O\({}_{2}\) (412.08) calculated: C: 43.72%, H: 2.94%, N: 6.80%; found: C: 43.86%, H: 2.93%, N: 6.77%. IR (cm\({}^{-1}\)): 3182 (NH), 3064, 3025 (CH, arom.