The synthetic experiments were accomplished at Nizhyn Mykola Gogol State University. All solvents used in the experiment were purified according to the standard procedures. Carbonyl compounds 5 used in the synthesis of the target ylidenes were obtained from commercial sources and used without further purification. 4-Amino-6-tert-butyl-3-methylthio-4H-[1,2,4]triazin-5-one (1) was obtained by the method previously described (Schmidt et al. 1982). Hydrazinolysis of 4-amino-6-tert-butyl-3-methylthio-4H-[1,2,4]triazin-5-one (1) giving compound 2 was carried out by refluxing 3-methylthio derivative 1 with an excess of hydrazine hydrate in propanol-2 (El Massry et al. 2012).
NMR spectra were recorded on a Varian Unity Plus 400 spectrometer (400.4 MHz for 1H and 100.7 MHz for 13C) and Bruker DRX500 (500.13 MHz) in DMSO-d6 using TMS as an internal standard. Chemical shifts are reported in ppm units with the use of the δ scale. The melting points were measured on a small-sized heating table with the observation device Electrothermal ІА 9200 (Electrothermal Engineering Ltd, Great Britain). Elemental analysis was performed on a EuroEA 3000 elemental analyzer.
The general procedure for the synthesis of 4-amino-3-(R-ylidenehydrazono)-6-tert-butyl-3,4-dihydro-2H-[1,2,4]triazin-5-ones 6–8
To a solution of 4-amino-6-tert-butyl-3-hydrazinyl-4H-[1,2,4]triazin-5-one (2) (1.98 g, 0.01 mol) in ethanol (50 ml) an aldehyde 5 (0.01 mol) was added. The reaction mixture was refluxed for 3 hours and evaporated to the volume of 15 ml. After cooling the residue to the room temperature precipitate of ylidenes 6–8 was formed. The solid was filtered off, washed with ethanol, dried on air, and recrystallized from ethanol or propanol-2.
4-Amino-6-tert-butyl-3-(furan-2-ylmethylenehydrazono)-3,4-dihydro-2H-[1,2,4]triazin-5-one (6a). Yield 1.52 g (55%), mp 196–197 °С (iPrOH). Anal. Calcd for C12H16N6O2: N 30.42. Found: N 30.63. 1H NMR (500 MHz, DMSO-d6) δ 1.31 (s, 9H, C(CH3)3), 5.72 (s, 2H, NH2), 6.58–7.72 (m, 3H, furyl), 8.13 (s, 1H, = CH), 12.1 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 28.4(C(CH3)3), 37.8(C(CH3)3), 112.4, 118.6, 134.4, 144.1(3-C), 148.8, 150.7, 153.1(3-C), 159.6(C = O).
4-Amino-6-tert-butyl-3-(thiophen-2-ylmethylenehydrazono)-3,4-dihydro-2H-[1,2,4]triazin-5-one (6b). Yield 1.66 g (57%), mp 177–178 °С (propanole-2). Anal. Calcd for C12H16N6OS: N 28.75. Found: N 28.68. 1H NMR (500 MHz, DMSO-d6) δ 1.31 (s, 9H, C(CH3)3), 5.97 (s, 2H, NH2), 7.16 (t, J 4.4 Hz, 1H, H-4 thienyl), 7.56 (d, J 3.9 Hz, 1H, thienyl), 7.77 (d, J 5.1 Hz, 1H, thienyl), 8.06 (s, 1H, = CH), 12.6 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 28.7(C(CH3)3), 36.7(C(CH3)3), 124.0, 126.7, 128.3, 130.2 (C = N), 144.6, 151.2(6-C), 153.0(3-C), 159.4(C = O).
4-Amino-3-(2-benzylidenehydrazono)-6-tert-butyl-3,4-dihydro-2H-[1,2,4]triazin-5-one (7a). Yield 1.86 g (65%), mp 136–137 °С (iPrOH). Anal. Calcd for C14H18N6O: N 29.35. Found: N 29.11. 1H NMR (400 MHz, DMSO-d6) δ 1.36 (s, 9H, C(CH3)3), 5.77 (s, 2H, NH2), 7.34–7.93 (m, 5H, ArH), 8.27 (s, 1H, = CH), 12.3 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 27.6(C(CH3)3), 37.1(C(CH3)3), 127.3, 128.6, 131.7, 133.1, 151.9(6-C), 158.0(C = N), 160.1(3-C), 162.3(C = O).
4-Amino-3-(4-bromobenzylidenehydrazono)-6-tert-butyl-3,4-dihydro-2H-[1,2,4]triazin-5-one (7b). Yield 2.59 g (71%), mp 203–204 °С (EtOH). Anal. Calcd for C14H17BrN6O: N 23.01. Found: N 23.30. 1H NMR (400 MHz, DMSO-d6) δ 1.44 (s, 9H, C(CH3)3), 6.14 (s, 2H, NH2), 7.01 (d, J 8.3 Hz, 2H, ArH), 7.43 (d, J 8.3 Hz, 2H, ArH), 8.95 (s, 1H, = CH), 12.3 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 27.5(C(CH3)3), 36.7(C(CH3)3), 123.8, 128.1, 130.6, 131.9, 150.7(6-C), 154,8(3-C), 157.7(C = N), 163.4(C = O).
4-Amino-3-(4-hydroxybenzylidenehydrazono)-6-tert-butyl-3,4-dihydro-2H-[1,2,4]triazin-5-one (7c). Yield 2.08 g (69%), mp 203–204 °С (EtOH). Anal. Calcd for C14H18N6O2: N 27.80. Found, %: N 27.58. 1H NMR (400 MHz, DMSO-d6) δ 1.34 (s, 9H, C(CH3)3), 5.60 (s, 2H, NH2), 6.75 (d, J 8.8 Hz, 4H, ArH), 7.65 (d, J 8.8 Hz, 4H, ArH), 8.15 (s, 1H, = CH), 9.28 (s, 1H, OH), 11.6 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 26.8(C(CH3)3), 37.6(C(CH3)3), 116.1, 125.7, 130.9, 149.8(6-C), 153.7(3-C), 159.1(C = N), 160.3(C = O), 164.5(C-OH).
4-Amino-3-(2-hydroxybenzylidenehydrazono)-6-tert-butyl-3,4-dihydro-2H-[1,2,4]triazin-5-one (7d). Yield 1.81 g (60%), mp 163–164 °С (EtOH). Anal. Calcd for C14H18N6O2: N 27.80. Found: N 27.93. 1H NMR (400 MHz, DMSO-d6) δ 1.35 (s, 9H, C(CH3)3), 5.79 (s, 2H, NH2), 6.83–7.57 (m, 4H, ArH), 8.49 (s, 1H, = CH), 9.91 (s, 1H, OH), 12.5 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 27.6(C(CH3)3), 36.8(C(CH3)3), 116.9, 117.8, 121.9, 125.7, 132.8, 145.7(C-OH), 150.7(6-C), 153.8(3-C), 156.2(C = N), 159.7(C = O).
4-Amino-3-(4-hydroxy-3-methoxybenzylidenehydrazono)-6-tert-butyl-3,4-dihydro-2H-[1,2,4]triazin-5-one (7e). Yield 2.16 g (65%), mp 215–216 °С (EtOH). Anal. Calcd for C15H20N6O3: N 25.29. Found, %: N 25.61. 1H NMR (500 MHz, DMSO-d6) δ 1.32 (s, 9H, C(CH3)3), 3.86 (s, 3H, OCH3), 5.77 (s, 2H, NH2), 6.77 (d, J 7.9 Hz, 1H, ArH), 7.10 (d, J 7.9 Hz, 1H, ArH), 7.76 (s, 1H, H-2 benzylidene), 8.15 (s, 1H, = CH), 8.86 (s, 1H, OH), 12.3 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 27.6(C(CH3)3), 38.4(C(CH3)3), 58.1(OCH3), 111.4, 116.5, 121.7, 129.4, 143.5(C-OCH3), 147.8(C-OH), 149.4(C = N), 150.7(6-C), 153.1(3-C), 158.7(C = O).
4-Amino-3-(3-hydroxy-4-methoxybenzylidenehydrazono)-6-tert-butyl-3,4-dihydro-2H-[1,2,4]triazin-5-one (7f). Yield 2.09 g (63%), mp 166–167 °С (EtOH). Anal. Calcd for C15H20N6O3: N 25.29. Found: N 25.45. 1H NMR (500 MHz, DMSO-d6) δ 1.31 (s, 9H, C(CH3)3), 3.82 (s, 3H, OCH3), 5.76 (s, 2H, NH2), 6.94 (d, J 8.2 Hz, 1H, ArH), 7.23 (d, J 8.2 Hz, 1H, ArH), 7.47 (s, 1H, H-2 benzylidene), 8.17 (s, 1H, = CH), 9.36 (s, 1H, OH), 12.3 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 28.4(C(CH3)3), 37.7(C(CH3)3), 56.0(OCH3), 111.7, 115.7, 122.1, 131.6, 146.1(C-OCH3), 147.1(C-OH), 150.6(C = N), 151.7(6-C), 153.1 (3-C), 158.6(C = O).
Methyl 4-[((4-amino-6-(tert-butyl)-5-oxo-4,5-dihydro-1,2,4-triazin-3(2H)-ylidene)hydrazono)methyl]benzoate (7g). Yield 2.09 g (68%), mp 204–205 °С (MeOH). Anal. Calcd for C16H20N6O3: N 24.40. Found: N 24.63. 1H NMR (400 MHz, DMSO-d6) δ 1.33 (s, 9H, C(CH3)3), 3.87 (s, 3H, CO2CH3), 5.84 (s, 2H, NH2), 7.97 (d, J 8.4 Hz, 2H, ArH), 8.13 (d, J 8.4 Hz, 2H, ArH), 8.37 (s, 1H, = CH), 12.5 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 27.5(C(CH3)3), 37.4(C(CH3)3), 51.3(COOCH3), 128.3, 130.7, 132.4, 138.5, 151.8(6-C), 153.7(3-C), 159.4(5-C = O), 162.4(C = N), 165.8(COOCH3).
4-Amino-3-(2-nitrobenzylidenehydrazono)-6-tert-butyl-3,4-dihydro-2H-[1,2,4]triazin-5-one (7h). Yield 2.32 g (70%), mp 227–228 °С (EtOH). Anal. Calcd for C14H17N7O3: N 29.59. Found: N 29.86. 1H NMR (500 MHz, DMSO-d6) δ 1.32 (s, 9H, C(CH3)3), 5.85 (s, 2H, NH2), 7.61–8.74 (m, 4H, ArH), 8.59 (s, 1H, = CH), 12.5 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 26.3(C(CH3)3), 35.7(C(CH3)3), 122.8, 128.8, 130.1, 131.7, 134.4, 143.1(C = N), 147.5(C-NO2), 150.7(6-C), 152.5(3-C), 158.5(C = O).
4-Amino-3-(3-nitrobenzylidenehydrazono)-6-tert-butyl-3,4-dihydro-2H-[1,2,4]triazin-5-one (7i). Yield 2.42 g (73%), mp 146–147 °С (EtOH). Anal. Calcd for C14H17N7O3: N 29.59. Found: N 29.52. 1H NMR (500 MHz, DMSO-d6) δ 1.32 (s, 9H, C(CH3)3), 5.83 (s, 2H, NH2), 7.67–8.92 (m, 4H, ArH), 8.44 (s, 1H, = CH), 12.7 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 26.5(C(CH3)3), 36.8(C(CH3)3), 120.6, 126.4, 128.5, 132.8, 134.6, 146.2(C-NO2), 148.4(C = N), 151.7(6-C), 153.5(3-C), 157.5(C = O).
4-Amino-3-(4-nitrobenzylidenehydrazono)-6-tert-butyl-3,4-dihydro-2H-[1,2,4]triazin-5-one (7j). Yield 2.55 g (77%), mp 194–195 °С (EtOH). Anal. Calcd for C14H17N7O3: N 29.59. Found: N 29.91. 1H NMR (500 MHz, DMSO-d6) δ 1.33 (s, 9H, C(CH3)3), 5.85 (s, 2H, NH2), 7.83 (d, J 8.8 Hz, 2H, ArH), 8.31 (d, J 8.8 Hz, 2H, ArH), 8.46 (s, 1H, = CH), 12.6 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 26.5(C(CH3)3), 38.1(C(CH3)3), 123.4, 123.5, 125.4, 125.5, 138.2, 150.1(C-NO2), 150.6(6-C), 153.5(3-C), 157.5(C = N), 162.5(C = O).
4-Amino-3-(2-hydroxynaphthalene-1-ylmethylenehydrazono)-6-tert-butyl-3,4-dihydro-2H-[1,2,4]triazin-5-one (8). Yield 2.26 g (64%), mp 234–235 °С (iPrOH). Anal. Calcd for C18H20N6O2: N 23.85. Found, %: N 23.58. 1H NMR (500 MHz, DMSO-d6) δ 1.33 (s, 9H, C(CH3)3), 5.91 (s, 2H, NH2), 7.21–8.39 (m, 6H, naphthyl), 9.34 (s, 1H, = CH), 11.5 (s, 1H, OH), 12.6 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 27.6(C(CH3)3), 36.6(C(CH3)3), 107.4, 117.5, 120.6, 122.7, 126.0, 127.5, 128.6, 132.7, 133.4, 142.7(C = N), 150.2(6-C), 152.4(3-C), 158.4(C = O), 171.4(C-OH).
Synthesis of 6-tert-butyl-4-((2-methoxybenzylidene)amino)-3-(2-methoxybenzylidenehydrazono)-3,4-dihydro-2H-[1,2,4]triazin-5-one (9). To a solution of 4-amino-6-tert-butyl-3-hydrazinyl-4H-[1,2,4]triazin-5-one (3) (1.98 g, 0.01 mol) in ethanol (50 ml) 2-methoxybenzaldehyde (2.72 g, 0.02 mol) was added. The reaction mixture was refluxed for 5 hours and evaporated to the volume of 15 ml. After cooling the residual solution to the room temperature, the precipitate of 9 was formed. The solid was filtered off, washed with ethanol, dried on air and recrystallized from ethanol.
Yield 2.43 g (56%), mp 198–199 °С (EtOH). Anal. Calcd for C23H26N6O3: N 19.34. Found, %: N 19.60. 1H NMR (400 MHz, DMSO-d6) δ 1.33 (s, 9H, C(CH3)3), 3.79 (s, 3H, OCH3), 3.89 (s, 3H, OCH3), 6.96 (t, J 7.5 Hz, 1H, ArH), 7.02 (d, J 8.4 Hz, 1H, ArH), 7.13 (t, J 7.5 Hz, 1H, ArH), 7.22 (d, J 8.4 Hz, 1H, ArH), 7.36 (t, J 8.4 Hz, 1H, ArH), 7.64 (t, J 7.8 Hz 1H, ArH), 8.07 (d, J 7.8 Hz, 1H, ArH), 8.38 (d, J 7.8 Hz, 1H, ArH), 8.45 (s, 1H, = CH), 8.84 (s, 1H, = CH), 12.3 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 29.3(C(CH3)3), 36.7(C(CH3)3), 55.4(OCH3), 110.5, 115.9, 120.6, 131.6, 132.5, 142.7, 145.1, 150.5(6-C), 152.8(3-C), 156.5(C-OCH3), 164.2(C = O).
The general procedure for the synthesis of 3-(2-(het)arylidenehydrazinyl)-6-tert-butyl-2H-[1,2,4]triazin-5-ones 10–12 and 14
To a solution of 6-tert-butyl-3-hydrazinyl-4H-[1,2,4]triazin-5-one (4) (1.83 g, 0.01 mol) in ethanol (50 ml) an aldehyde 5 or a methyl ketone 13 (0.01 mol) was added. The reaction mixture was refluxed for 3 hour and evaporated to the volume of 15 ml. After cooling of the residual solution to the room temperature the precipitate of a corresponding ylidene 10–12, 14 was formed. The solid was filtered off, washed with ethanol, dried on air and recrystallized from methanol, DMF or acetic acid.
6-tert-Butyl-3-(2-(furan-2-ylmethylene)hydrazinyl)-2H-[1,2,4]triazin-5-one (10a). Yield 1.59 g (61%), mp 253–254 °С (MeOH). Anal. Calcd for C12H15N5O2: N 26.80. Found, %: N 26.64. 1H NMR (500 MHz, DMSO-d6) δ 1.31 (s, 9H, C(CH3)3), 6.59–7.72 (m, 3H, furyl), 7.97 (s, 1H, = CH), 11.4 (s, 1H, NH), 12.4 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 26.5(C(CH3)3), 37.5(C(CH3)3), 114.4, 117.7, 135.3(C = N), 142.5(5-furan), 149.5(2-furan), 152.4(6-C), 153.4(3-C), 164.4(C = O).
6-tert-Butyl-3-(2-(thiophen-2-ylmethylene)hydrazinyl)-2H-[1,2,4]triazin-5-one (10b). Yield 1.80 g (65%), mp > 260 °С (MeOH). Anal. Calcd for C12H15N5OS: N 25.25. Found: N 25.54. 1H NMR (500 MHz, DMSO-d6) δ 1.30 (s, 9H, C(CH3)3), 7.11 (t, J 3.9 Hz, 1H, H-5 thienyl), 7.49 (d, J 3.9 Hz, 1H, thienyl), 7.66 (d, J 5.0 Hz, 1H, thienyl), 8.23 (s, 1H, = CH), 11.6 (s, 1H, NH), 12.6 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 25.6(C(CH3)3), 39.5(C(CH3)3), 124.7, 126.5, 128.5, 132.6, 143.7(2-thiophene), 150.6(6-C), 152.8(3-C), 164.4(C = O).
3-(2-Benzylidenehydrazinyl)-6-tert-butyl-2H-[1,2,4]triazin-5-one (11a). Yield 1.87 g (69%), mp > 260 °С (MeOH). Anal. Calcd for C14H17N5O: N 25.81. Found: N 25.56. 1H NMR (400 MHz, DMSO-d6) δ 1.33 (s, 9H, C(CH3)3), 7.39–7.96 (m, 5H, ArH), 8.08 (s, 1H, = CH), 11.6 (s, 1H, NH), 12.8 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 25.8(C(CH3)3), 36.5(C(CH3)3), 124.4, 124.5, 127.5, 127.6, 130.7, 132.8, 150.8(3-C), 153.7(6-C), 161.1(C = N), 161.8(C = O).
3-(2-(4-Bromobenzylidene)hydrazinyl)-6-tert-butyl-2H-[1,2,4]triazin-5-one (11b). Yield 2.73 g (78%), mp > 260 °С (DMF). Anal. Calcd for C14H16BrN5O: N 20.00. Found: N 20.22. 1H NMR (500 MHz, DMSO-d6) δ 1.31 (s, 9H, C(CH3)3), 7.62 (d, J 8.5 Hz, 2H, ArH), 7.89 (d, J 8.5 Hz, 2H, ArH), 8.01 (s, 1H, = CH), 11.7 (s, 1H, NH), 12.8 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 25.6(C(CH3)3), 35.2(C(CH3)3), 123.9, 126.7, 129.5, 130.5, 150.9(3-C), 153.6(6-C), 160.5(C = N), 163.5(C = O).
3-(2-(4-Hydroxybenzylidene)hydrazinyl)-6-tert-butyl-2H-[1,2,4]triazin-5-one (11c). Yield 2.18 g (76%), mp > 260 °С (DMF). Anal. Calcd for C14H17N5O2: N 24.38. Found: N 24.70. 1H NMR (500 MHz, DMSO-d6) δ 1.31 (s, 9H, C(CH3)3), 6.77 (d, J 8.8 Hz, 2H, ArH), 7.69 (d, J 8.8 Hz, 2H, ArH), 7.94 (s, 1H, = CH), 9.64 (s, 1H, OH), 11.3 (s, 1H, NH), 12.5 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 26.6(C(CH3)3), 37.0(C(CH3)3), 114.6, 126.7, 132.5, 150.3(3-C), 152.9(6-C), 160.8(C = N), 162.3(C = O), 164.1(C-O).
3-(2-(2-Hydroxybenzylidene)hydrazinyl)-6-tert-butyl-2H-[1,2,4]triazin-5-one (11d). Yield 1.52 g (53%), mp > 260 °С (DMF). Anal. Calcd for C14H17N5O2: N 24.38. Found: N 24.63. 1H NMR (500 MHz, DMSO-d6) δ 1.31 (s, 9H, C(CH3)3), 6.82–8.12 (m, 4H, ArH), 8.37 (s, 1H, = CH), 9.89 (s, 1H, OH), 11.5 (s, 1H, NH), 12.7 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 26.5(C(CH3)3), 35.6(C(CH3)3), 117.5, 118.6, 121.0, 127.7, 132.9, 145.7, 150.8(3-C), 154.8(6-C), 158.2(C-O), 164.5(C = O).
3-(2-(4-Hydroxy-3-methoxybenzylidene)hydrazinyl)-6-tert-butyl-2H-[1,2,4]triazin-5-one (11e). Yield 1.78 g (56%), mp > 260 °С (DMF). Anal. Calcd for C15H19N5O3: N 22.07. Found: N 22.00. 1H NMR (500 MHz, DMSO-d6) δ 1.32 (s, 9H, C(CH3)3), 3.83 (s, 3H, OCH3), 6.85–8.09 (m, 3H, ArH), 8.41 (s, 1H, = CH), 9.83 (s, 1H, OH), 11.3 (s, 1H, NH), 12.6 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 26.5(C(CH3)3), 35.8(C(CH3)3), 53.6(OCH3), 112.8, 116.2, 122.0, 130.7, 145.9, 148.6(C-OCH3), 151.0(C-OH), 151.1(3-C), 152.6(6-C), 165.4(C = O).
3-(2-(3-Hydroxy-4-methoxybenzylidene)hydrazinyl)-6-tert-butyl-2H-[1,2,4]triazin-5-one (11f). Yield 1.87 g (59%), mp > 260 °С (DMF). Anal. Calcd for C15H19N5O3: N 22.07. Found: N 22.41. 1H NMR (500 MHz, DMSO-d6) δ 1.30 (s, 9H, C(CH3)3), 3.82 (s, 3H, OCH3), 6.95 (d, J 8.5 Hz, 1H, ArH), 7.22 (d, J 8.5 Hz, 1H, ArH), 7.42 (s, 1H, H-2 ArH), 7.90 (s, 1H, = CH), 8.94 (s, 1H, OH), 11.4 (s, 1H, NH), 12.7 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 25.6(C(CH3)3), 34.9(C(CH3)3), 58.7(OCH3), 112.9, 114.9, 121.9, 130.7, 146.8(C = N), 148.6(C-OH), 150.6(C-OCH3),, 152.0(3-C), 153.8(6-C), 163.7(C = O).
Methyl 4-((2-(6-(tert-butyl)-5-oxo-2H-1,2,4-triazin-3-yl)hydrazono)methyl)benzoate (11g). Yield 2.17 g (66%), mp > 260 °С (DMF). Anal. Calcd for C16H19N5O3: N 21.26. Found: N 21.6. 1H NMR (400 MHz, DMSO-d6) δ 1.32 (s, 9H, C(CH3)3), 3.88 (s, 3H, CO2CH3), 7.97 (d, J 8.4 Hz, 2H, ArH), 8.03 (d, J 8.4 Hz, 2H, ArH), 8.10 (s, 1H, = CH), 11.7 (s, 1H, NH), 12.7 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 27.0(C(CH3)3), 38.6(C(CH3)3), 52.7(COOCH3), 127.6, 129.6, 131.8, 138.5, 149.6(3-C), 150.6(6-C), 160.7(C = N), 162.8(5-C = O), 168.5(COOCH3).
6-tert-Butyl-3-(2-(2-nitrobenzylidene)hydrazinyl)-2H-[1,2,4]triazin-5-one (11h). Yield 2.28 g (72%), mp > 260 °С (DMF). Anal. Calcd for C14H16N6O3: N 26.57. Found: N 26.48. 1H NMR (500 MHz, DMSO-d6) δ 1.31 (s, 9H, C(CH3)3), 7.61 (t, J 8.7 Hz, 1H, ArH), 7.73 (t, J 8.7 Hz, 1H, ArH), 8.01 (d, J 8.7 Hz, 1H, ArH), 8.50 (s, 1H, = CH), 8.68 (d, J 8.7 Hz, 1H, ArH), 11.8 (s, 1H, NH), 12.8 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 26.5(C(CH3)3), 37.2(C(CH3)3), 123.0, 126.9, 128.9, 130.9, 132.6, 142.9, 147.7(C-NO2), 151.9(3-C), 152.7(6-C), 163.6(C = O).
6-tert-Butyl-3-(2-(3-nitrobenzylidene)hydrazinyl)-2H-[1,2,4]triazin-5-one (11i). Yield 2.40 g (76%), mp > 260 °С (DMF). Anal. Calcd for C14H16N6O3: N 26.57. Found: N 26.81. 1H NMR (500 MHz, DMSO-d6) δ 1.32 (s, 9H, C(CH3)3), 7.69 (t, J 8.4 Hz, 1H, H-5 ArH), 8.17 (s, 1H, = CH), 8.19 (d, J 8.4 Hz, 1H, ArH), 8.24 (d, J 8.4 Hz, 1H, ArH), 8.86 (s, 1H, H-2 ArH), 11.7 (s, 1H, NH), 12.9 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 27.5(C(CH3)3), 35.6(C(CH3)3), 120.6, 124.9, 127.8, 132.6, 133.4, 144.9(C = N), 147.5(C-NO2), 151.1(3-C), 152.8(6-C), 164.2(C = O).
6-tert-Butyl-3-(2-(4-nitrobenzylidene)hydrazinyl)-2H-[1,2,4]triazin-5-one (11j). Yield 2.56 g (81%), mp > 260 °С (DMF). Anal. Calcd for C14H16N6O3: N 26.57. Found: N 26.67. 1H NMR (500 MHz, DMSO-d6) δ 1.32 (s, 9H, C(CH3)3), 8.14 (s, 1H, = CH), 8.18 (d, J 8.7 Hz, 2H, ArH), 8.23 (d, J 8.7 Hz, 2H, ArH), 11.8 (s, 1H, NH), 12.8 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 26.7(C(CH3)3), 39.4(C(CH3)3), 124.7, 124.9, 137.5, 149.7, 151.9(3-C), 154.9(6-C), 160.8(C = N), 163.6(C = O).
6-tert-Butyl-3-(2-(2-methoxybenzylidene)hydrazinyl)-2H-[1,2,4]triazin-5-one (11k). Yield 1.87 g (62%), mp > 260 °С (DMF). Anal. Calcd for C15H19N5O2: N 23.24. Found: N 23.53. 1H NMR (500 MHz, DMSO-d6) δ 1.30 (s, 9H, C(CH3)3), 3.83 (s, 3H, OCH3), 6.98 (t, J 7.7 Hz, 1H, ArH), 7.06 (d, J 8.2 Hz, 1H, ArH), 7.38 (t, J 8.2 Hz, 1H, ArH), 8.31 (d, J 7.7 Hz, 1H, ArH), 8.40 (s, 1H, = CH), 11.5 (s, 1H, NH), 12.7 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 24.1(C(CH3)3), 35.7(C(CH3)3), 56.0(OCH3), 109.7, 116.2, 120.6, 131.7, 132.0, 145.1(C = N), 150.2(3-C), 152.7(6-C), 156.9(C-OCH3), 160.5(C = O).
6-tert-Butyl-3-(2-(4-methoxybenzylidene)hydrazinyl)-2H-[1,2,4]triazin-5-one (11l). Yield 1.87 g (62%), mp > 260 °С (MeOH). Anal. Calcd for C15H19N5O2: N 23.24. Found: N 23.03. 1H NMR (500 MHz, DMSO-d6) δ 1.31 (s, 9H, C(CH3)3), 3.80 (s, 3H, OCH3), 7.93 (d, J 8.8 Hz, 2H, ArH), 8.71 (d, J 8.8 Hz, 2H, ArH), 8.00 (s, 1H, = CH), 11.3 (s, 1H, NH), 12.5 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 26.4(C(CH3)3), 37.7(C(CH3)3), 58.2(OCH3), 113.6, 125.9, 130.2, 148.5(3-C), 153.8(6-C), 160.7(C = N), 162.7(C = O), 165.5(C-OCH3),
6-tert-Butyl-3-(2-(3-ethoxy-4-hydroxybenzylidene)hydrazinyl)-2H-[1,2,4]triazin-5-one (11m). Yield 1.99 g (60%), mp 258–259 °С (MeOH). Anal. Calcd for C16H21N5O3: N 21.13. Found: N 21.34. 1H NMR (500 MHz, DMSO-d6) δ 1.31 (s, 9H, C(CH3)3), 1.37 (t, J 6.8 Hz, 3H, CH2CH3), 4.11 (s, J 6.8 Hz, 2H, CH2CH3), 6.78 (d, J 8.0 Hz, 1H, ArH), 7.03 (d, J 8.0 Hz, 1H, ArH), 7.67 (s, 1H, H-2 ArH), 7.90 (s, 1H, = CH), 9.37 (s, 1H, OH), 11.4 (s, 1H, NH), 12.7 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 12.6(OCH2CH3),, 26.3(C(CH3)3), 36.9(C(CH3)3), 64.3(OCH2CH3), 111.4, 117.5, 121.5, 130.2, 143.5(C = N), 147.5(C-OCH2CH3), 150.2(3-C), 152.8(6-C), 155.2(C-OH), 163.5(C = O).
6-tert-Butyl-3-(2-((2-hydroxynaphthalen-1-yl)methylene)hydrazinyl)-2H-[1,2,4]triazin-5-one (12). Yield 2.33 g (69%), mp > 260 °С (DMF). Anal. Calcd for C18H19N5O2: N 20.7. Found: N 20.4. 1H NMR (500 MHz, DMSO-d6) δ 1.32 (s, 9H, C(CH3)3), 7.19 (d, J 8.9 Hz, 1H, naphthyl), 7.38 (t, J 8.9 Hz, 1H, naphthyl), 7.55 (t, J 8.9 Hz, 1H, naphthyl), 7.81 (d, J 8.0 Hz, 1H, naphthyl), 7.83 (d, J 8.9 Hz, 1H, naphthyl), 8.41 (d, J 8.0 Hz, 1H, naphthyl), 9.09 (s, 1H, = CH), 10.5 (s, 1H, OH), 11.4 (s, 1H, NH), 12.8 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 26.8(C(CH3)3), 38.1(C(CH3)3), 107.9, 117.2, 120.1, 123.9, 125.0, 127.5, 127.9, 131.1, 132.6, 141.1(C = N), 151.8(3-C), 151.9(6-C), 161.7(C = O), 174.5(C-OH).
6-tert-Butyl-3-(2-isopropylidenehydrazinyl)-2H-[1,2,4]triazin-5-one (14a). Yield 1.09 g (49%), mp > 260 °С (MeOH). Anal. Calcd for C10H17N5O: N 31.37. Found: N 31.70. 1H NMR (500 MHz, DMSO-d6) δ 1.31 (s, 9H, C(CH3)3), 1.92 (s, 3H, CH3), 2.00 (s, 3H, CH3), 10.3 (s, 1H, NH), 12.1 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 18.6, 24.5, 27.9(C(CH3)3), 36.2(C(CH3)3), 151.4(3-C), 153.0(C = N), 152.7(6-C), 163.2(C = O).
6-tert-Butyl-3-(2-(1-(1-hydroxynaphthalene-2-yl)ethylidene)hydrazinyl)-2H-[1,2,4]triazin-5-one (14b). Yield 2.00 g (57%), mp > 260 °С (MeOH). Anal. Calcd for C19H21N5O2: N 19.93. Found: N 19.98. 1H NMR (500 MHz, DMSO-d6) δ 1.30 (s, 9H, C(CH3)3), 2.49 (s, 3H, CH3), 7.38–8.30 (m, 6H, naphthyl), 10.4 (s, 1H, OH), 11.2 (s, 1H, NH), 12.3 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 16.6, 26.4(C(CH3)3), 35.2(C(CH3)3), 112.5, 120.7, 124.3, 124.6, 127.4, 127.5, 127.7, 128.6, 136.4, 150.8(3-C), 152.7(6-C), 161.1(C = N), 163.2(C = O), 167.5(C-OH).
6-tert-Butyl-3-(2-(1-phenylethylidene)hydrazinyl)-2H-[1,2,4]triazin-5-one (14c). Yield 1.57 g (55%), mp 251–252 °С (AcOH). Anal. Calcd for C15H19N5O: N 24.54. Found: N 24.72. 1H NMR (500 MHz, DMSO-d6) δ 1.32 (s, 9H, C(CH3)3), 2.30 (s, 3H, CH3), 7.78–8.07 (m, 5H, ArH), 11.4 (s, 1H, NH), 12.6 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 16.2, 27.5(C(CH3)3), 36.5(C(CH3)3), 125.7, 127.6, 131.9, 137.8, 147.5(C = N), 151.6(3-C), 153.2(6-C), 163.9(C = O).
6-tert-Butyl-3-(2-(1-(p-tolyl)ethylidene)hydrazinyl)-2H-[1,2,4]triazin-5-one (14d). Yield 1.70 g (57%), mp 227–228 °С (MeOH). Anal. Calcd for C16H21N5O: N 23.39. Found: N 23.11. 1H NMR (500 MHz, DMSO-d6) δ 1.34 (s, 9H, C(CH3)3), 2.29 (s, 3H, CH3), 2.37 (s, 3H, CH3), 7.34 (d, J 8.3 Hz, 2H, ArH), 7.91 (d, J 8.3 Hz, 2H, ArH), 10.7 (s, 1H, NH), 12.4 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 15.4, 21.0, 27.2(C(CH3)3), 37.7(C(CH3)3), 126.0, 128.2, 133.3, 135.1, 148.8(C = N), 150.7(3-C), 152.7(6-C), 163.6(C = O).
6-tert-Butyl-3-(2-(1-(4-tert-butylphenyl)ethylidene)hydrazinyl)-2H-[1,2,4]triazin-5-one (14e). Yield 1.74 g (51%), mp > 260 °С (MeOH). Anal. Calcd for C19H27N5O: N 20.51. Found: N 20.29. 1H NMR (500 MHz, DMSO-d6) δ 1.33 (s, 9H, C(CH3)3), 1.34 (s, 9H, C(CH3)3), 2.30 (s, 3H, CH3), 7.14 (d, J 8.4 Hz, 2H, ArH), 7.90 (d, J 8.4 Hz, 2H, ArH), 10.7 (s, 1H, NH), 12.4 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 15.4, 26.7(C(CH3)3), 31.1, 34.5, 36.6(C(CH3)3), 125.6, 128.2, 133.1, 145.5(C = N), 149.1(C-tBu), 152.2(3-C), 152.3(6-C), 163.3(C = O).
6-tert-Butyl-3-(2-(1-(4-chlorophenyl)ethylidene)hydrazinyl)-2H-[1,2,4]triazin-5-one (14f). Yield 1.95 g (61%), mp 262–263 °С (MeOH). Anal. Calcd for C15H18ClN5O: N 21.90. Found: N 22.21. 1H NMR (500 MHz, DMSO-d6) δ 1.31 (s, 9H, C(CH3)3), 2.29 (s, 3H, CH3), 7.43 (d, J 8.7 Hz, 2H, ArH), 8.10 (d, J 8.7 Hz, 2H, ArH), 10.8 (s, 1H, NH), 12.7 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 15.1, 28.1(C(CH3)3), 36.3(C(CH3)3), 125.5, 127.8, 135.7, 136.1, 148.5(C = N), 150.6(3-C), 154.1(6-C), 161.5(C = O).
6-tert-Butyl-3-(2-(1-(4-bromophenyl)ethylidene)hydrazinyl)-2H-[1,2,4]triazin-5-one (14g). Yield 2.58 g (71%), mp > 260 °С (MeOH). Anal. Calcd for C15H18BrN5O: N 19.23. Found: N 19.50. 1H NMR (500 MHz, DMSO-d6) δ 1.34 (s, 9H, C(CH3)3), 2.30 (s, 3H, CH3), 7.48 (d, J 8.8 Hz, 2H, ArH), 7.99 (d, J 8.8 Hz, 2H, ArH), 10.8 (s, 1H, NH), 12.5 (s, 1H, NH). 13C NMR (100 MHz, DМSО-d6) δ 14.8, 28.4(C(CH3)3), 36.3(C(CH3)3), 124.9, 127.1, 134.1, 134.6, 149.2(C = N), 150.6(3-C), 153.1(6-C), 162.9(C = O).