Chemistry
Chemical were purchased from Merck Chemical Company. Melting points (˚C) were determined by the Electrothermal IA9300 apparatus. (Cole-Parmer, Staffordshire, UK). Infrared spectra (IR) were recorded on a Perkin-Elmer 843 spectrometer employing potassium bromide (KBr) as the diluent (PerkinElmer, UK). Proton nuclear magnetic resonance (1H-NMR) spectra were acquired using the Bruker AVance series; AV-300, AV-500, and AV-600 MHz Spectrometer and benchtop NMR spectrometer, the NMReady-60 NMRPro spectrometer. Dimethylsulfoxide (DMSO-d6) solution and tetramethylsaline were utilized as an internal standard. Coupling constant values (J) are given in Hertz. Peak positions are expressed in parts per million (δ). Splitting patterns are as follows: s, singlet; d, doublet; t, triplet; q, quadruplet; dd, double doublet; m, multiplet. Mass spectra were obtained by Agilent 6410 Triple Quad LC MASS equipped with Electrospray Ionization (ESI) and Agilent 7000 Triple Quad GC MASS provided Electronic Ionization (EI). (Santa Clara, United States) The development of all reactions was monitored by thin-layer chromatography (TLC) performed on aluminium sheets coated with silica and visualized by UV irradiation.
Synthesis of arylhydrazones derivitives 1a-1j
Phenyl hydrazine (0.005 mole, 0.54 g) was added to a stirring solution of corresponding aldehyde (0.005 mole) in distilled water (10mL) and in the presence of 2mL glacial acetic acid (as the catalyst). The mixture stirred at room temperature (RT). Once the solid was formed, completion of the reaction was confirmed by carrying out the TLC sample. Next, the precipitate was filtered off, washed with cold water, dried under vacuum, and recrystallized with appropriate solvents.
Compound 1j was synthesized in a different proportion of 0.005 moles of aldehyde (Glyoxal) and 0.01 mole of phenylhydrazine under the same condition described above.
N-(4-((2-phenylhydrazono)methyl)phenyl)acetamide ( 1a ) Yield: 70%; m.p. 200°C; Recrystallization solvent: ethanol: water (1:1); 1HNMR (600 MHz, [D6] DMSO): δ = 10.194 (s, 1H; N-NH), 10.001(s, 1H; NH-CO), 7.787 (s, 1H; C=N), 7.59(d, 3JH,H=8.4 Hz, 2H; Ph2-H3, Ph2-H5), 7.548(d, 3JH,H =8.4 Hz ,2H; Ph2-H2, Ph2-H6), 7.188(t, 3JH,H =7.2-7.8 Hz, 2H; Ph1-H3, Ph1-H5), 7.03( d, 3JH,H =7.8 Hz, 2H; Ph1-H2, Ph1-H6), 6.71( t, 3JH,H =7.2, 1H; Ph1-H4), 2.037 ppm (s, 3H; CH3); IR (KBr): ν˜=3265 (s) (NH), 3183 (m) (CH, aromatic), 3098 (m) (CH, aliphatic), 1657 (vs) cm-1 (C=N); GC-MS (EI) m/z (%): 253 (100) [M+H]+; elemental analysis calcd (%) for C15H15N3O: C 71.13, H 5.97, N 16.59; found: C 71.21, H 5.96, N 16.53.
1-(3-nitrobenzylidene)-2-phenylhydrazine ( 1b ) Yield: 40%; m.p. 122-125°C; Recrystallization solvent: ethanol: water (1:1); 1HNMR (300 MHz, [D6] DMSO): δ = 10.64 (s,1H; NH), 8.39(s, 1H; Ph2-H2), 8.061(m, 2H; Ph2-H4, Ph2-H6), 7.92 (s, 1H; CH=N), 7.624 (t, 3JH,H =8.1 Hz, 1H; Ph2-H5), 7.216 (t, 3JH,H =7.5 Hz, 2H; Ph1-H3, Ph1-H5), 7.082(d, 3JH,H =7.8 Hz, 2H; Ph1-H2, Ph1-H6), 6.763 ppm (t, 3JH,H =7.2 Hz, 1H; Ph1-H4); IR (KBr): ν˜=3319 (s) (NH), 1528 (vs) (C=N), 1499 and 1343(s) (NO2), 692, 739 and 816 (m) cm-1 (metha substituted phenyl); GC-MS (EI) m/z (%): 241(100) [M+H]+; elemental analysis calcd (%) for C13H11N3O2: C 64.72, H 4.60, N 17.42; found: C 64.75, H 4.59, N 17.36.
1-(3-methoxybenzylidene)-2-phenylhydrazine ( 1c ) Yield: 50%; m.p. 51-53°C; Recrystallization solvent: ethanol: water (1:1); 1HNMR (300 MHz, [D6] DMSO): δ = 10.32 (s, 1H; NH), 7.82(s, 1H; CH=N), 7.27(m,3H; Ph2-H2, Ph2-H5, Ph2-H6), 7.18-7.2(t,2H; Ph1-H3, Ph1-H5), 7.06(d, 3JH,H =7.5 Hz, 2H; Ph1-H2, Ph1-H6), 6.85(d, 1H; 3JH,H =7.9 Hz, Ph2-H4), 6.738(t, 3JH,H =7.2 Hz, 1H; Ph1-H4), 3.81 ppm (s, 3H; OCH3); IR (KBr): ν˜=3310 (m) (NH), 1588 (vs) (C=N), 1263 and 1033 (s) (Ar-O-CH3), 697, 760 and 792 cm-1 (m) (metha substituted phenyl); GC-MS (EI) m/z (%): 226 (100) [M+H]+; elemental analysis calcd (%) for C14H14N2O: C 74.31, H 6.24, N 12.38; found: C 74.3, H 6.23, N 12.4.
1-phenyl-2-(3, 4, 5-trimethoxybenzylidene)hydrazine ( 1d ) Yield: 30%; m.p. 130-133°C; Recrystallization solvent: ethanol: water (1:1); 1HNMR (300 MHz, [D6] DMSO): δ = 10.27 (s, 1H; NH), 7.77(s, 1H; CH=N), 7.18-7.23(t, 3JH,H =7.5-7.8 Hz, 2H; Ph1-H3, Ph1-H5), 7.06(d, 3JH,H =7.8 Hz, 2H; Ph1-H2, Ph1-H6), 6.94(s, 2H; Ph2-H2, Ph2-H6), 6.728(t, 3JH,H =7.2 Hz, 1H; Ph1-H4), 3.82(s, 6H; OCH3, Meta, ortho), 3.67 ppm (s, 3H; OCH3 para); IR (KBr): ν˜=3339 (m) (NH), 3300 (w) (CH, aromatic), 2975 (w) (CH, aliphatic), 1632 (vs) (C=N), 1249 and 1024 cm-1 (s) (Ar-O-CH3); GC-MS (EI) m/z (%): 286.1 (100) [M+H]+; elemental analysis calcd (%) for C16H18N2O3: C 67.12, H 6.34, N 9.78; found: C 67.2, H 6.33, N 9.77.
1-(2-chlorobenzylidene)-2-phenylhydrazine ( 1e ) Yield: 80%; m.p. 81-85°C; Recrystallization solvent: ethanol: water (1:1); 1HNMR (300 MHz, [D6] DMSO): δ = 10.67(s, 1H; NH), 8.19(s, 1H; CH=N), 7.99-8.02(d, 3JH,H =7.8 Hz, 1H; Ph2-H3), 7.43(d, 3JH,H =7.65 Hz, 1H; Ph2-H6), 7.23(t, 3JH,H =7.5 Hz, 2H; Ph1-H3, Ph1-H5), 7.33(m,2H; Ph2-H4, Ph2-H5), 7.08(d, 3JH,H =7.5 Hz, 2H; Ph1-H2, Ph-H6), 6.77 ppm (t, 3JH,H =7.2 Hz, 1H; Ph1-H4); IR (KBr): ν˜=3116 (w) (NH) 1607 (s) (C=N), 765 (s) cm-1 (C-Cl); MS (ESI) m/z (%): 231 (100) [M+H]+; elemental analysis calcd (%) for C13H11ClN2: C 67.68, H 4.81, N 12.14; found: C 67.67, H 4.81, N 12.10.
4-((2-phenylhydrazono)methyl)benzoic acid ( 1f ) Yield: 23%; m.p. 221-225°C; Recrystallization solvent: ethanol: water (1:1); 1HNMR (300 MHz, [D6] DMSO): δ = 12.86(s, 1H; COOH), 10.58(s, 1H; NH), 7.91 (d, 3JH,H =8.4 Hz, 2H; Ph2-H3, Ph2-H5), 7.886(s, 1H; CH=N), 7.73(d, 3JH,H =8.4 Hz, 2H; Ph2-H2, Ph2-H6), 7.23(t, 3JH,H =7.8 Hz, 2H; Ph1-H3, Ph1-H5), 7.09(d, 3JH,H =7.8 Hz, 2H; Ph1-H2, Ph1-H6), 6.77 ppm (t, 3JH,H =7.2 Hz, 1H; Ph1-H4); IR (KBr): ν˜=3323 (br) (OH and NH), 3073 (w) (CH, aromatic), 1712 (m) (C=O), 1680 (s) (C=N) 767 and 699 (s) cm-1 (mono substituted phenyl); MS (ESI) m/z (%): 241 (100) [M+H]+; elemental analysis calcd (%) for C14H12N2O2: C 69.99, H 5.03, N 11.66; found: C 70.07, H 5.04, N 11.62.
2-methoxy-4-(2-phenylhydrazono)methyl phenol ( 1g ) Yield: 42%; m.p. 65-66°C (lit[26] m.p. 64-65°C); Recrystallization solvent: methanol: water (3:2); 1HNMR (100 MHz, [D6] CDCl3): δ = 7.5-7.75 (s, 1H; CH=N), 6.75-7.40 (m, 10H; Ar H,CH=N and NH), 5.80-5.85 (s, 1H; OH), 3.85-4.00 (s, 3H; CH3); IR (KBr): ν˜=3532 (br) (OH), 3342 (m) (NH), 3083 (w) (CH, aromatic), 2969 (w) (CH, aliphatic), 1611 (vs) (C=N), 1276 and 1046 cm-1 (s) (Ar-O-CH3); MS (ESI) m/z (%): 243 (100) [M+H]+; elemental analysis calcd (%) for C14H14N2O2: C 69.41, H 5.82, N 11.56; found: C 96.41, H 5.81, N 11.6.
2-((2-phenylhydrazono)methyl)-1H-pyrrole ( 1h ) Yield: 70%; m.p. 137-140°C; Recrystallization solvent: ethanol; 1HNMR (600 MHz, [D6] DMSO): δ = 11.09 (s, 1H; NH pyrrole), 7.71 (s, 1H; CH=N), 9.87 (s, 1H; NH), 7.157 (t, 3JH,H =7.8 Hz, 2H; Ph1-H3, Ph1-H5), 7.027 (d, 2H; 3JH,H =7.8 Hz, Ph1-H2, Ph1-H6), 6.799(s, 1H; H3 pyrrole), 6.66 (t, 1H; 3JH,H =7.2 Hz, Ph1-H4), 6.23(s, 1H; H4 pyrrole), 6.05 ppm (d, 1H; H5 pyrrole); IR (KBr): ν˜=3432 (m) (NH), 3327 (w) (CH, aromatic), 1600 (vs) (C=N) 749 and 695 (s) cm-1 (mono substituted phenyl); MS (ESI) m/z (%): 185 (100) [M+H]+; elemental analysis calcd (%) for C11H11N3: C 71.33, H 5.99, N 22.69; found: C 71.29, H 5.99, N 22.72.
3-((2-phenylhydrazono) methyl)-1H-indole ( 1i ) Yield: 70%; m.p. 200-204°C; Recrystallization solvent: methanol: water (3:2); 1HNMR (300 MHz, [D6] DMSO): δ = 11.29 (s, 1H; NH indole), 9.79(s,1H; NH), 8.244(d, 1H; J=6, H5 indole), 8.10(s, 1H, C=N), 7.61(d, 1H; H6 indole), 7.41(d, 3JH,H =6.15 Hz, 1H; H4 indole), 7.17(m, 4H; Ph1-H3, Ph1-H5,H3 indole, H9 indole), 7.03(d, J=7.8 Hz, 2H, Ph1-H2, Ph1-H6), 6.67 ppm (t, 3JH,H =7.2 Hz, 1H; Ph1-H4); IR (KBr): ν˜=3456 (s) (NH), 3312 (m) (CH, aromatic), 1610 (vs) (C=N), 1490 (m) (NH, indole ring), 782 (vs) cm-1 (CH out of plane bending, indole ring); GC-MS (EI) m/z (%): 236 (100) [M+H]+; elemental analysis calcd (%) for C15H13N3: C 76.57, H 5.57, N 17.86; found: C 76.58, H 5.58, N 17.84.
1,2-bis(2-phenylhydrazono)ethane ( 1j ) Yield: 13%; m.p. 179-179.9°C; Recrystallization solvent: ethanol; 1HNMR (600 MHz, [D6] DMSO): δ = 10.35 (s, 1H; NH), 7.63(s, 1H; CH=N), 7.19(t, 3JH,H =7.2-7.8 Hz, 2H; Ph1-H3, Ph1-H5), 6.97(d, 3JH,H =7.8 Hz, 2H; Ph1-H2, Ph1-H6), 6.73 ppm (t, 3JH,H =7.2 Hz, 1H; Ph1-H4); IR (KBr): ν˜=3319 (m) (NH), 3043 (w) (CH, aromatic), 1604 (vs) (C=N) 767 and 698 (s) cm-1 (mono substituted phenyl); GC-MS (EI) m/z (%): m/z= 238 (60) [M+H]+; elemental analysis calcd (%) for C14H14N4: C 70.57, H 5.92, N 23.51; found: C 70.55, H 5.92, N 23.53.
Synthesis of N-isonicotinohydrazide derivatives 2a-2l
Isonicotinic acid hydrazide (0.005 mole, 0.68 g) was added slowly to a stirring solution of appropriate aldehyde (0.005 mole) in distilled water (10mL) and in presence of 2mL glacial acetic acid (as catalyst). The mixture stirred at room temperature (RT). Once the solid was formed, completion of the reaction was confirmed by carrying out the TLC sample. Next, the precipitate was filtered off, washed with cold water, dried under vacuum, and recrystallized with appropriate solvents.
N-(4-((2-isonicotinoylhydrazono)methyl)phenyl)acetamide ( 2a ) Yield: 91%; mp 288-292°C; Recrystallization solvent: ethanol; 1HNMR (60 MHz, [D6] DMSO): δ = 12.0 (s, 1H; N-NH), 10.2(s, 1H; NH amide), 7.5–8.5 (m, 9H; phenyl and pyridine H, and CH=N), 2 ppm (s, 3H; CH3); IR (KBr): ν˜= 3303 (s) (NH, amide), 3035 (m) (CH, aromatic), 2926 (w) (CH, aliphatic), 1659 (vs) (C=O amide), 1582 (vs) (C=N), 843 (s) cm-1 (CH out of plane bending, 4-substituted pyridine); MS (ESI) m/z (%): 283 (100) [M+H]+; elemental analysis calcd (%) for C15H14N4O2: C 63.82, H 5.00, N 19.85; found: C 63.81, H 4.99, N 19.84.
N'-(3-nitrobenzylidene)isonicotinohydrazide ( 2b ) Yield: 70%; m.p. 227-230°C; Recrystallization solvent: ethanol; 1HNMR (500 MHz, [D6] DMSO): δ = 12.32 (s, 1H; NH), 8.79-8.80(d, 3JH,H =4.5 Hz, 2H; pyridine-H3,-H5), 8.573(s, 2H; CH=N, Ph-H2), 8.27-8.29(d, 3JH,H =8 Hz, 1H; Ph-H4), 8.17-8.19(d, 3JH,H =8 Hz,1H; Ph-H6), 7.82-7.83(d, 3JH,H =4.5 Hz, 2H; pyridine-H2,-H6), 7.75-7.81 ppm (t, 3JH,H =8 Hz,1H; Ph-H5); IR (KBr): ν˜=3423 (s) (NH, amide), 3208 (m) (CH, aromatic), 3034 (m) (CH, aliphatic), 1663 (vs) (C=O amide), 1525 (vs) (C=N), 1500 and 1350 (m) (NO2) 850 (w) cm-1 (CH out of plane bending, 4-substituted pyridine); MS (ESI) m/z (%): 271 (100) [M+H]+; Anal.Calcd for C13H10N4O3: C 57.78, H 3.73, N 20.73; found: C 57.79, H 3.72, N 20.74.
N'-(3-methoxybenzylidene)isonicotinohydrazide ( 2c ) Yield: 32%; m.p. 218-222°C; Recrystallization solvent: ethanol; 1HNMR (60 MHz, [D6] DMSO): δ = 12.2 (s, 1H; N-NH), 7.5 – 8.5 (m, 9H; phenyl and pyridine H, CH=N), 3 ppm (s, 3H; OCH3); IR (KBr): ν˜=3549 (s) (NH, amide), 3182 (w) (CH, aromatic), 3058 (w) (CH, aliphatic), 1659 (vs) (C=O, amide), 1588 (s) (C=N), 1290 and 1053 (s) (Ar-O-CH3), 859 cm-1 (CH out of plane bending, 4-substituted pyridine); MS (ESI) m/z (%): 260 (100) [M+H]+; elemental analysis calcd (%) for C14H13N3O2: C 65.87, H 5.13, N 16.46; found: C 65.88, H 5.12, N 16.47.
N'-(2-nitrobenzylidene)isonicotinohydrazide ( 2d ) Yield: 70%; m.p. 225-229°C (Lit.[27]m.p. 226-228°C); Recrystallization solvent: ethanol; 1HNMR (60 MHz, [D6] DMSO): δ = 12.1 (s, 1H; N-NH), 7.5 – 8.5 ppm (m, 9H; phenyl and pyridine H, CH=N); IR (KBr): ν˜=3431 (s) (NH, amide), 3167 (m) (CH, aromatic), 2994 (m) (CH, aliphatic), 1655 (vs) (C=O, amide), 1570 (s) (C=N), 1513 and 1346 (s) (NO2), 844 (w) cm-1 (CH out of plane bending, 4-substituted pyridine); MS (ESI) m/z (%): 271 (100) [M+H]+; elemental analysis calcd (%) for C13H10N4O3: C 57.78, H 3.73, N 20.73; found: C 57.79, H 3.72, N 20.8.
N'-(4-hydroxy-3-methoxybenzylidene)isonicotinohydrazide ( 2e ) Yield: 30%; m.p. 217-220°C; Recrystallization solvent: 1-propanol; 1H NMR (300 MHz, [D6] DMSO): δ = 11.86 (s, 1H; -NH-N=), 8.76 (d, 3JH,H = 4.3 Hz, 2H; pyridine), 8.34 (s, 1H; -N=C-H), 7.80 (d, 2H; pyridine, J = 3.9 Hz), 7.32 (s, 1H; benzylidene), 7.09 (d, 3JH,H = 8.2 Hz, 2H; benzylidene), 5.08 (s, 1H; OH, D2O exchangeable), 3.82 ppm (s, 3H; CH3);[28] IR (KBr): ν˜=3527 (m) (OH), 3459 (m) (NH amide), 3075 (m) (CH aromatic), 1669 (s) (C=O, amide), 1593 (s) (C=N), 1285 (s) cm-1 (Ar-O-C); MS (ESI) m/z (%): 272 (100) [M+H]+;elemental analysis calcd (%) for C14H13N3O3: C 61.99, H 4.83, N 15.49; found: C 61.97, H 4.82, N 15.51.
N'-((1H-pyrrol-2-yl) methylene)isonicotinohydrazide ( 2f ) Yield: 26%; m.p. 232-233°C (Lit.[29]m.p.. 230-232°C); Recrystallization solvent: 1-propanol; 1HNMR (60 MHz, [D6] DMSO): δ = 12 (s, 2H; N-NH), 7.5 – 8.5 ppm (m, 8H; pyrrole and pyridine H, CH=N); IR (KBr): ν˜=3401(m) (NH, amide), 3211 (m) (CH, aromatic), 2973 (m) (CH, aliphatic), 1660 (s) (C=O, amide), 1610 (s) (C=N), 845 (w) cm-1 (CH out of plane bending, 4-substituted pyridine); MS (ESI) m/z (%): 215 (100) [M+H]+; elemental analysis calcd (%) for C11H10N4O: C 61.67, H 4.71, N 26.15; found: C 61.68, H 4.72, N 26.14.
N'-((E)-3-phenylallylidene)isonicotinohydrazide ( 2g ) Yield: 40%; m.p. 199-203°C; Recrystallization solvent: ethanol; 1HNMR (60 MHz, [D6] DMSO): δ = 12 (s, 1H; N-NH), 7-9 ppm (m, 12H; phenyl and pyridine H, CH=N, CH2=CH2); IR (KBr): ν˜=3495 (m) (NH, amide), 3236 (m) (CH, aromatic), 2987 (m) (CH, aliphatic), 1672 (s) (C=O, amide), 1645 (s) (C=N), 843 (w) cm-1 (CH out of plane bending, 4-substituted pyridine); MS (ESI) m/z (%): 252 (100) [M+H]+; elemental analysis calcd (%) for C15H13N3O: C 71.70, H 5.21, N 16.72; found: C 71.7, H 5.21, N 16.74.
N'-(pyridin-3-ylmethylene)isonicotinohydrazide ( 2h ) Yield: 34%; m.p. 239-243°C; Recrystallization solvent: 1-propanol; 1HNMR (60 MHz, [D6] DMSO): δ = 12.2 (s, 1H; N-NH), 7.5 – 8.5 ppm (m. 9H; pyridine H, CH=N); IR (KBr): ν˜=3192 (m) (NH, amide), 3009 (m) (CH, aromatic), 2936 (m) (CH, aliphatic), 1678 (vs) (C=O, amide), 1594 (m) (C=N), 849 (m) (CH out of plane bending, 4-substituted pyridine), 822 (w) cm-1 (CH out of plane bending, 3-substituted pyridine); MS (ESI) m/z (%): 227 (100) [M+H]+; elemental analysis calcd (%) for C12H10N4O: C 63.71, H 4.46, N 24.76; found: C 63.83, H 4.45, N 24.67.
N'-(pyridin-4-ylmethylene)isonicotinohydrazide ( 2i ) Yield: 34%; m.p. 231-235°C; Recrystallization solvent: 1-propanol; 1HNMR (60 MHz, [D6] DMSO): δ = 12.2 (s, 1H; N-NH), 7.5 – 8.5 ppm (m, 9H; pyridine H, CH=N); IR (KBr): ν˜=3480 (m) (NH, amide), 3196 (m) (CH, aromatic), 3017 (m) (CH, aliphatic), 1669 (s) (C=O, amide), 1574 (s) (C=N), 836 (w) cm-1 (CH out of plane bending, 4-substituted pyridine); MS (ESI) m/z (%): 227 (100) [M+H]+; elemental analysis calcd (%) for C12H10N4O: C 63.71, H 4.46, N 24.76; found: C 63.72, H 4.47, N 24.76.
N'-(4-nitrobenzylidene)isonicotinohydrazide ( 2j ) Yield: 93%; m.p. 195-200°C; Recrystallization solvent: ethanol; 1HNMR (60 MHz, [D6] DMSO): δ = 12.2 (s, 1H; N-NH), 7.5 – 8.5 ppm (m, 9H; phenyl and pyridine H, CH=N); IR (KBr): ν˜=3196 (w) (NH, amide), 3000 (w) (CH, aromatic), 2904 (w) (CH, aliphatic), 1684 (vs) (C=O, amide), 1570 (s) (C=N), 1514 and 1342 (vs) (NO2), 856 (m) cm-1 (CH out of plane bending, 4-substituted pyridine); MS (ESI) m/z (%): 271 (100) [M+H]+; elemental analysis calcd (%) for C13H10N4O3: C 57.78, H 3.73, N 20.73; found: C 57.77, H 3.73, N 20.72.
N'-benzylideneisonicotinohydrazide ( 2k ) Yield: 60%; m.p. 198-200°C; Recrystallization solvent: ethanol; 1H-NMR (60 MHz, [D6] DMSO): δ = 12.06 (s, 1H; N–H), 8.80 (d, 3JH,H = 6 Hz, 2H; aromatic H), 8.48 (s, 1H; azomethine), 7.84–7.74 (m, 4H; aromatic), 7.49–7.46 ppm (m, 3H; aromatic);[30] IR (KBr): ν˜=3408 (m) (NH, amide), 3197 (m) (CH, aromatic), 3031 (m) (CH, aliphatic), 1668 (s) (C=O, amide), 1575 (m) (C=N), 847 (w) (CH out of plane bending, 4-substituted pyridine), 707 and 690 (m) cm-1 (mono substitution phenyl group); MS (ESI) m/z (%): 226 (100) [M+H]+; elemental analysis calcd (%) for C13H11N3O: C 69.32, H 4.92, N 18.66; found: C 69.33, H 4.91, N 18.65.
N'-([1,1'-biphenyl]-4-ylmethylene)isonicotinohydrazide ( 2l ) Yield: 70%; m.p. 218-221°C; 1HNMR (60 MHz, [D6] DMSO): δ = 12 (s, 1H; N-NH), 8.5(m, 3H; pyridine-H3, -H5, CH=N), 7.5 ppm (m, 11H; pyridine-H2, -H6, phenyl groups H); IR (KBr): ν˜=3413 (m) (NH, amide), 3022 (m) (CH, aromatic), 2930 (m) (CH, aliphatic), 1666 (s) (C=O, amide), 1597 (m) (C=N), 839 (w) cm-1 (CH out of plane bending, 4-substituted pyridine); MS (ESI) m/z (%): 302 (100) [M+H]+; elemental analysis calcd (%) for C19H15N3O: C 75.73, H 5.02, N 13.94; found: C 75.74, H 5.03, N 13.92.