## 2 Materials and Methods
### Synthesis
\(N\)-ethyl-\(N^{\prime}\)-(4-fluorobenzylidene)-5-oxo-1-(3,4,5-trimethoxyphenyl)pyrrolidine-3-carbohydrazide (**22**)  
White solid, yield 0.37 g (84%), m. p. 71-72 \({}^{\circ}\)C (from water-1,4-dioxane mixture). \({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\): 1.11 (t, J = 6.9 Hz, 3H, CH\({}_{3}\)), 2.72-2.88 (m, 2H, CH\({}_{2}\)CO), 3.63, 3.75 (2s, 9H, 3 OCH\({}_{3}\)), 3.97-4.16 (m, 4H, NCH\({}_{2}\), CH\({}_{2}\)), 4.26-4.38 (m, 1H, CH), 6.98 (s, 2H, H\({}_{\rm Ar}\)), 7.23 (t, J = 8.5 Hz, 2H, H\({}_{\rm Ar}\)), 7.82-7.92 (m, 2H, H\({}_{\rm Ar}\)), 8.12 (s, 1H, CH=N) ppm. \({}^{13}\)C NMR (101 MHz, DMSO-\(d_{6}\)) \(\delta\): 10.94, 33.27, 35.23, 35.75, 50.79, 55.90, 60.09, 98.08, 115.73, 115.94, 129.21, 129.29, 131.44, 131.47, 134.29, 135.26, 139.42, 152.66, 161.69, 164.15, 171.87, 172.70 ppm. IR (KBr): \(\gamma_{\rm max}\): 1681 (2C=O), 1270, 1260, 1238 (3 OCH\({}_{3}\)) cm\({}^{-1}\). Anal. Calcd. for C\({}_{23}\)H\({}_{26}\)FN\({}_{3}\)O\({}_{5}\), %: C 62.29; H 5.91; N 9.48. Found: C 62.19; H 5.82; N 9.39. 4-(3,5-Dimethyl-1\(H\)-pyrazole-1-carbonyl)-1-(3,4,5-trimethoxyphenyl)pyrrolidin-2-one (**23**)  
A mixture of hydrazide **4** (0.98 g, 3.2 mmol), 2,4-pentanedione (0.5 g, 5.2 mmol), and propan-2-ol (10 mL) was refluxed for 3 h. The solvent was evaporated under reduced pressure until dryness was achieved, and the oily product was triturated with hexane. The obtained solid was filtered off and washed with hexane and ethyl ether. The crude product was purified by recrystallization from propan-2-ol. Light brown powder, yield 0.82 g (70%), m. p. 120-121 \({}^{\circ}\)C.  
\({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\): 2.22, 2.51 (2s, 6H, 2 CH\({}_{3}\)), 2.78-2.94 (m, 2H, CH\({}_{2}\)CO), 4.02-4.23 (m, 2H, NCH\({}_{2}\)), 3.64, 3.77 (2s, 9H, 3 OCH\({}_{3}\)), 4.44-4.55 (m, 1H, CH), 6.25 (s, 1H, C=CH), 6.98 (s, 2H, H\({}_{\rm Ar}\)) ppm. \({}^{13}\)C NMR (101 MHz, DMSO-\(d_{6}\)) \(\delta\): 13.58, 14.07, 35.18, 35.29, 50.57, 55.92, 60.10, 98.16, 111.69, 134.37, 135.08, 143.90, 152.19, 152.68, 171.46, 172.71 ppm. IR (KBr): \(\gamma_{\rm max}\): 1720, 1710 (2C=O), 1272, 1255, 1238 (3 OCH\({}_{3}\)) cm\({}^{-1}\). Anal. Calcd. for C\({}_{19}\)H\({}_{23}\)N\({}_{3}\)O\({}_{5}\), %: C 61.12; H 6.21; N 11.25. Found: C 60.97; H 6.14; N 11.15. _N-(2,5-dimethyl-1\(H\)-pyrrol-1-yl)-5-oxo-1-(3,4,5-trimethoxyphenyl)pyrrolidine-3-carboxamide (**24**)  
To a solution of hydrazide **4** (1.0 g, 3.2 mmol) in propan-2-ol (10 mL), 2,5-hexanedione (0.74 g, 6.5 mmol) and glacial acetic acid (0.5 mL) were added. The reaction mixture was stirred and refluxed for 3 h. Then, it was cooled to room temperature, the precipitated product was filtered off, washed with water and ethyl ether, and recrystallized from a 1,4-dioxane-water mixture or toluene. Light brown powder, yield 0.95 g (76%), m. p. 149-150 \({}^{\circ}\)C.  
\({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\): 2.00 (s, 6H, 2 CH\({}_{3}\)), 2.67-2.94 (m, 2H, CH\({}_{2}\)CO), 3.39-3.51 (m, 1H, CH), 3.64, 3.78 (2s, 9H, 3 OCH\({}_{3}\)), 3.97-4.16 (m, 2H, NCH\({}_{2}\)), 5.65 (s, 2H, CH=CH), 6.99 (s, 2H, H\({}_{\rm Ar}\)), 10.90 (s, 1H, NH) ppm. \({}^{13}\)C NMR (101 MHz, DMSO-\(d_{6}\)) \(\delta\): 10.94, 10.99, 33.99, 36.00, 50.65, 55.93, 60.12, 98.11, 103.10, 126,75, 134.37, 135.13, 152.70, 171.39, 172.89 ppm. IR (KBr): \(\gamma_{\rm max}\): 3260 (CONH), 1709 (2C=O), 1271, 1239 (3 OCH\({}_{3}\)) cm\({}^{-1}\). Anal. Calcd. for C\({}_{20}\)H\({}_{25}\)N\({}_{3}\)O\({}_{5}\), %: C 62.00; H 6.50; N 10.85. Found: C 61.92; H 6.39; N 10.74. 4-(5-Thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)-1-(3,4,5-trimethoxyphenyl)pyrrolidin-2-one (**25**)  
To a solution of potassium hydroxide (1.8 g, 32 mmol) in methanol (40 mL), carbon disulfide (2.4 g, 32 mmol) was added dropwise. The obtained mixture was stirred at room temperature for 15-20 min, and the methanolic solution of acid hydrazide **4** (1 g, 3.2 mmol/15 mL) was poured over.