*3-(4-fluorophenyl)-5-(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbaldehyde (***3a***)*

Mp = 131–132 ◦C; Rf = 0.81; 1H NMR (300 MHz, ppm, DMSO-*d*6): 8.87 (s, 1H, −CHO); 7.86–7.84 (m, 2H, arom.), 7.33–7.32 (m, 2H, arom.), 7.17–7.15 (d, 2H, arom.), 6.90–6.89 (d, 2H, arom.), 5.50–5.47 (m, 1H, CH-pyr.), 3.91–3.86 (m, 1H, −CH2-pyr.), 3.73 (s, 3H, OCH3), 3.22–3.18 (m, 1H, CH2-pyr.); 13C NMR (DMSO-*d*6) δ (ppm): 164.1, 162.5, 159.5, 158.6, 155.2, 133.3, 129.2, 129.1, 127.0, 115.9, 115.8, 114.0, 58.1, 55.1, 42.3; MS: *m*/*z* calcd for [C17 H15FN2O2]+ ([M+H]+/ M++ H+Na): 298.31, found 299.0/321.20.
