Chemistry

Melting points were measured with a Stuart melting point apparatus and are uncorrected. The IR spectra were recorded using a FTIR Bruker–vector 22 spectrophotometer as KBr pellets. The 1H and 13C NMR spectra were recorded in CDCl3 and DMSO as solvents on Varian Gemini NMR spectrometer at 300 MHz using TMS as internal standard. Chemical shifts are reported as δ values in ppm. Mass spectra were recorded with a Shimadzu GCMS–QP–1000 EX mass spectrometer in EI (70 eV) model. The elemental analyses were performed at the Microanalytical Center, Cairo University.

Synthesis of (E)-3-heteroaryl-1-(3-(furan-2-yl)-5-methyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl)prop-2-en-1-one derivatives (7a-h)

To a stirred mixture of 4-acetyl-1-(4-nitrophenyl)-1H-pyrazole 5 (0.001 mol) and the appropriate heteroaldehydes 6 (0.001 mol) in ethanol (30 ml), sodium hydroxide solution 20% was added, and the reaction mixture was stirred for 6 h at room temperature and left overnight. The resulting solid product that precipitated was filtered, washed with water, and crystallized from a suitable solvent to give the corresponding chalcones 7a-h.

(E)-3-(Furan-2-yl)-1-(3-(furan-2-yl)-5-methyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl)prop-2-en-1-one (7a)

Yellow crystals, mp 138–140 °C (EtOH-Dioxane), Yield (80%); IR (νmax, cm−1) ν 1659 (CO). 1H NMR (300 MHz, CDCl3) δ 2.60 (s, 3H, CH3), 6.47–6.49 (m, 2H, furan-H), 6.65 (d, 1H, furan-H, J = 3.3 Hz), 6.84 (d, 2H, furan-H, J = 3.6 Hz), 6.86 (d, 1H, vinyl-H, J = 16.2 Hz), 7.42 (m, 1H, furan-H, J = 3.6 Hz), 7.47 (d, 1H, vinyl-H, J = 16.2 Hz), 7.74 (d, 2H, Ar–H, J = 9 Hz), 8.37 (d, 2H, Ar–H, J = 9 Hz); 13C NMR (75 MHz, CDCl3) δ 12.6, 111.0, 111.3, 112.5, 115.9, 121.0, 123.5, 124.6, 125.4, 129.5, 142.8, 143.1, 143.4, 143.6, 144.9, 145.9, 146.7, 151.1, 186.9. MS (EI, 70 eV) m/z (%): 389 (M+). Anal. Calcd. for C21H15N3O5 (389.37): C, 64.78; H, 3.88; N, 10.79. Found: C, 64.91; H, 3.97; N, 10.93.

(E)-1-(3-(Furan-2-yl)-5-methyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl)-3-(thiophen-2-yl)prop-2-en-1-one (7b)

Yellow crystals, mp 142–144 °C (EtOH-Dioxane), Yield (85%); IR (νmax, cm−1) ν 1658 (CO). 1H NMR (300 MHz, CDCl3) δ 2.61 (s, 3H, CH3), 6.51–6.59 (m, 1H, furan-H), 6.74 (d, 1H, vinyl-H, J = 15.3 Hz), 6.83 (d, 1H, thiophene-H, J = 3.3 Hz), 7.04–7.07 (m, 1H, thiophene-H), 7.26 (d, 1H, thiophene-H, J = 2.7 Hz), 7.38 (d, 1H, furan-H, J = 4.8 Hz), 7.55 (m, 1H, furan-H), 7.74 (d, 2H, Ar–H, J = 9 Hz), 7.81 (d, 1H, vinyl-H, J = 15.3 Hz), 8.40 (d, 2H, Ar–H, J = 9 Hz); 13C NMR (75 MHz, CDCl3) δ 12.6, 111.1, 111.3, 120.9, 124.5, 124.7, 125.3, 128.2, 128.8, 131.6, 135.4, 139.9, 143.20, 143.27 143.31, 143.6, 145.8, 146.7, 186.4. MS (EI, 70 eV) m/z (%): 405 (M+). Anal. Calcd. for C21H15N3O4S (405.43): C, 62.21; H, 3.73; N, 10.36;. Found: C, 62.32; H, 3.94; N, 10.43.

(E)-1-(3-(Furan-2-yl)-5-methyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl)-3-(pyridin-4-yl)prop-2-en-1-one (7c)

Yellow crystals, mp 198–200 °C (EtOH-Dioxane), Yield (82%); IR (νmax, cm−1) ν 1653 (CO). 1H NMR (300 MHz, CDCl3) δ 2.64 (s, 3H, CH3), 6.56–6.57 (m, 1H, furan-H), 6.85 (d, 1H, furan-H, J = 3.5 Hz), 7.07 (d, 1H, vinyl-H, J = 15.9 Hz), 7.25 (d, 2H, pyridine-H), 7.53 (d, 1H, vinyl-H, J = 15.9 Hz), 7.58 (m, 1H, furan-H), 7.74 (d, 2H, Ar–H, J = 9 Hz), 8.43 (d, 2H, Ar–H, J = 9 Hz), 7.38 (d, 2H, pyridine-H, J = 4.5 Hz); 13C NMR (75 MHz, CDCl3) δ 12.8, 111.1, 111.6, 121.7, 124.6, 125.4, 125.5, 129.5, 139.4, 141.8, 143.1, 143.8, 144.1, 145.7, 146.9, 149.3, 150.3, 186.2. MS (EI, 70 eV) m/z (%): 400 (M+). Anal. Calcd. for C22H16N4O4 (400.39): C, 66.00; H, 4.03; N, 13.99;. Found: C, 66.14; H, 4.11; N, 14.12.

(E)-3-(1,4-Diphenyl-1H-pyrazol-3-yl)-1-(3-(furan-2-yl)-5-methyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl)prop-2-en-1-one (7d)

Yellow crystals, mp 168–170 °C (Dioxane-EtOH), Yield (92%); IR (νmax, cm−1) ν 1652 (CO). 1H NMR (300 MHz, CDCl3) δ 2.57 (s, 3H, CH3), 6.54–6.56 (m, 1H, furan-H), 6.79 (d, 1H, vinyl-H, J = 15.3 Hz), 6.85 (d, 1H, furan-H, J = 2.7 Hz), 7.35–7.78 (m, 14H, Ar–H + furan-H + vinyl-H), 8.15 (s, 1H, pyrazole-H5), 8.40 (d, 2H, Ar–H, J = 9 Hz); 13C NMR (75 MHz, CDCl3) δ 12.5, 110.9, 111.5, 117.8, 119.1, 120.9, 124.6, 125.4, 125.7, 126.4, 127.2, 128.51, 128.57, 128.61, 129.4, 131.9, 134.5, 139.2, 142.9, 143.2, 143.40, 143.47, 146.2, 146.8, 153.6, 187.6. MS (EI, 70 eV) m/z (%): 541 (M+). Anal. Calcd. for C32H23N5O4 (541.57): C, 70.97; H, 4.28; N, 12.93; Found: C, 71.12; H, 4.34; N, 12.78.

(E)-1-(3-(Furan-2-yl)-5-methyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl)-3-(1-phenyl-4-(p-tolyl)-1H-pyrazol-3-yl)prop-2-en-1-one (7e)

Yellow crystals, mp 248–250 οC (Dioxane-EtOH), Yield (87%); IR (νmax, cm−1) ν 1652 (CO). 1H NMR (300 MHz, CDCl3) δ 2.61 (s, 3H, CH3), 2.9 (s, 3H, CH3), 6.57–6.58 (m, 1H, furan-H), 6.79 (d, 1H, vinyl-H, J = 16.2 Hz), 6.84 (d, 1H, furan-H, J = 3 Hz), 7.40–7.81 (m, 11H, Ar–H + furan-H + vinyl-H), 8.14 (s, 1H, pyrazole-H5), 8.29 (d, 2H, Ar–H, J = 8.7 Hz), 8.42 (d, 2H, Ar–H, J = 9 Hz). MS (EI, 70 eV) m/z (%): 555 (M+). Anal. Calcd. for C33H25N5O4 (555.59): C, 71.34; H, 4.54; N, 12.61; Found: C, 71.50; H, 4.63; N, 12.77.

(E)-1-(3-(Furan-2-yl)-5-methyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl)-3-(4-(4-methoxyphenyl)-1-phenyl-1H-pyrazol-3-yl)prop-2-en-1-one (7f)

Yellow crystals, mp 232–234 °C (Dioxane-EtOH), Yield (84%); IR (νmax, cm−1) ν 1653 (CO). 1H NMR (300 MHz, CDCl3) δ 2.57 (s, 3H, CH3), 3.87 (s, 3H, OCH3), 6.55–6.56 (m, 1H, furan-H), 6.78 (d, 1H, vinyl-H, J = 16.2 Hz), 6.85 (d, 1H, furan-H, J = 3.6 Hz), 6.97 (d, 2H, Ar–H, J = 8.7 Hz), 7.34–7.72 (m, 9H, Ar–H + furan-H + vinyl-H), 7.75 (d, 2H, Ar–H, J = 6.9 Hz), 8.13 (s, 1H, pyrazole-H5), 8.40 (d, 2H, Ar–H, J = 8.7 Hz); 13C NMR (75 MHz, CDCl3) δ 12.5, 55.3, 111.1, 111.5, 114.1, 117.7, 119.2, 120.9, 124.5, 124.7, 125.5, 126.3, 127.2, 129.5, 129.8, 134.9, 135.8, 135.9, 139.3, 142.9, 143.3, 143.5, 146.3, 146.9, 153.6, 159.9, 187.8. MS (EI, 70 eV) m/z (%): 571 (M+). Anal. Calcd. for C33H25N5O5 (571.59): C, 69.34; H, 4.41; N, 12.25; Found: C, 69.49; H, 4.58; N, 12.34.

(E)-3-(4-(4-Chlorophenyl)-1-phenyl-1H-pyrazol-3-yl)-1-(3-(furan-2-yl)-5-methyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl)prop-2-en-1-one (7g)

Yellow crystals, mp 242–244 °C (Dioxane-EtOH), Yield (85%); IR (νmax, cm−1) ν 1655 (CO). 1H NMR (300 MHz, DMSO-d6) δ 2.50 (s, 3H, CH3), 6.61–6.62 (m, 1H, furan-H), 6.88 (d, 1H, furan-H, J = 3.6 Hz), 6.95 (d, 1H, vinyl-H, J = 15.9 Hz), 7.38–7.90 (m, 11H, Ar–H + furan-H + vinyl-H), 7.94 (d, 2H, Ar–H, J = 8.7 Hz), 8.42 (d, 2H, Ar–H, J = 8.7 Hz), 9.09 (s, 1H, pyrazole-H5). MS (EI, 70 eV) m/z (%): 576 (M+). Anal. Calcd. for C32H22ClN5O4 (576.01): C, 66.73; H, 3.85; N, 12.16; Found: C, 66.81; H, 3.98; N, 12.29.

(E)-1-(3-(Furan-2-yl)-5-methyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl)-3-(4-(4-nitrophenyl)-1-phenyl-1H-pyrazol-3-yl)prop-2-en-1-one (7h)

Yellow crystals, mp 242–242 οC (Dioxane-EtOH), Yield (83%); IR (νmax, cm−1) ν 1651 (CO). 1H NMR (300 MHz, CDCl3) δ 2.61 (s, 3H, CH3), 6.55–6.56 (m, 1H, furan-H), 6.84 (d, 1H, vinyl-H, J = 15.6 Hz), 6.86 (d, 1H, furan-H, J = 2.1 Hz), 7.11–7.77 (m, 12H, Ar–H + furan-H + vinyl-H), 7.88 (d, 1H, vinyl-H, J = 15.9 Hz), 8.1 (s, 1H, pyrazole-H5), 8.41 (d, 2H, Ar–H, J = 9 Hz); 13C NMR (75 MHz, CDCl3) δ 12.7, 111.2, 111.6, 117.8, 119.3, 121.0, 124.8, 125.6, 126.0, 126.3, 126.6, 127.0, 127.4, 127.8, 129.6, 133.7, 133.8, 139.1, 143.2, 143.4, 143.5, 146.3, 147.0, 147.9, 187.5. MS (EI, 70 eV) m/z (%): 586 (M+). Anal. Calcd. for C32H22N6O6 (586.56): C, 65.53; H, 3.78; N, 14.33; Found: C, 65.67; H, 3.89; N, 14.49.