Chemistry of Heterocyclic Compounds 2019, 55(10), 968–977
1
2
143.1; 152.5; 153.1; 157.5; 161.5. Found, m/z: 259.1190
[M+H]+. C13H15N4O2. Calculated, m/z: 259.1190. Found,
%: C 60.38; H 5.80; N 21.49. C13H14N4O2. Calculated, %:
C 60.46; H 5.46; N 21.69.
(1H, dd, J = 8.0, J = 1.6, H Ar); 9.19 (1H, s, H triazine).
13C NMR spectrum (CDCl3), δ, ppm: 14.4; 15.4; 19.7; 25.5;
65.0; 114.5; 121.4; 125.7; 132.4; 133.3; 143.9; 149.1; 158.1;
165.8; 202.1. Found, m/z: 303.1451 [M–H]. C15H20N4O3.
Calculated, m/z: 303.1452.
1-(3-Phenyl-1,2,4-triazin-5-yl)ethanone oxime (2e). Yield
0.87 g (41%), mp 198°C. IR spectrum, ν, cm–1: 3145, 2827,
Synthesis of σH-adducts (General method). A solution
of the appropriate 1,2,4-triazine 1b,d,e (1 mmol) and nitro-
ethane (0.225 g, 3 mmol) in DMSO (1 ml) was added in
one portion to a vigorously stirred suspension of powdered
K2CO3 (0.414 g, 3 mmol ) in dry DMSO (1 ml) at room
temperature. The mixture was stirred at room temperature
for 2.5 h, then poured into ice water (20 ml) and extracted
with Et2O. After evaporation of the solvent, the residue was
purified by column chromatography on silica gel, eluent
EtOAc–hexane, 1:1, to yield product as yellow crystals.
3-(2-Ethoxyphenyl)-5-(1-nitroethyl)-2,5-dihydro-1,2,4-
triazine (4a), mixture of diastereomers 1.3:1. Yield 0.19 g
(69%). Major diastereomer: Rf 0.78. IR spectrum, ν, cm–1:
1
1539, 1517, 1363, 1354, 1029, 756, 686. H NMR spectrum
(DMSO-d6), δ, ppm (J, Hz): 2.30 (3H, s, CH3); 7.60–7.62 (3H,
m, H Ph); 8.48 (2H, d, J = 8.0, H Ph); 9.62 (1H, s, H triazine);
12.67 (1H, s, OH). 13C NMR spectrum (CDCl3), δ, ppm: 9.0;
127.7; 129.0; 131.8; 134.5; 143.9; 152.5; 153.4; 162.1.
Found, m/z: 215.2747 [M+H]+. C12H14N4O. Calculated, m/z:
214.2749. Found, %: C 61.51; H 4.80; N 26.29. C11H10N4O.
Calculated, %: C 61.67; H 4.71; N 26.15.
1-[3-(Naphthalen-1-yl)-1,2,4-triazin-5-yl]ethanone oxime
(2f). Yield 1.34 g (51%), mp 196°C. IR spectrum, ν, cm–1:
3134, 3053, 2812, 1506, 1338, 1305, 1041, 1028, 767.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 2.42 (3H, s,
CH3); 7.52 –7.67 (3H, m, H Ar); 7.95–7.97 (1H, m, H Ar);
8.05–8.08 (1H, t, J = 7.2, H Ar); 8.24 (1H, d, J = 7.2,
H Ar); 8.71 (1H, d, J = 8.0, H Ar); 9.80 (1H, s, H triazine).
13C NMR spectrum (CDCl3), δ, ppm: 25.5; 124.8; 125.1;
125.2; 126.4; 127.6; 128.0; 128.8; 128.9; 130.8; 131.8;
132.3; 133.0; 134.1; 169.4. Found, m/z: 264.3310 [M+H]+.
C15H12N4O. Calculated, m/z: 264.3306. Found, %: C 68.42;
H 5.71; N 21.00. C15H12N4O. Calculated, %: C 68.17;
H 4.58; N 21.20.
1
3407, 2926, 1600, 1544, 1454, 1236, 1033, 750. H NMR
spectrum (CDCl3), δ, ppm (J, Hz): 1.32 (3H, t, J = 7.2,
1
CH3); 1.61 (3H, d, J = 6.8, CH3); 4.01 (1H, dd, J = 7.2,
2J = 2.0, CH); 4.07 (2H, q, J = 7.2, CH2); 4.92 (1H, p,
J = 6.8, CH); 6.82 (1H, d, J = 2.0, H triazine); 6.98 (1H, t,
J = 8.0, H Ar); 7.08 (1H, d, J = 8.0, H Ar); 7.36–7.44 (2H,
m, H Ar); 10.69 (1H, br. s, NH). 13C NMR spectrum (CDCl3),
δ, ppm: 15.3; 55.5; 83.1; 112.6; 119.8; 121.5; 131.4; 132.4;
133.7; 154.5; 156.9. Mass spectrum, m/z (Irel, %): 276 [M]+
(1), 229 (48), 202 (100), 174 (44), 148 (6), 120 (28), 91
(10), 39 (5). Minor diastereomer: Rf 0.69. IR spectrum,
ν, cm–1: 3409, 2920, 1602, 1546, 1451, 1230, 1028, 758.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 1.32 (3H, t,
J = 7.2, CH3); 1.54 (3H, d, J = 6.8, CH3); 4.07 (2H, q, J = 7.2,
1-[3-(2-Ethoxyphenyl)-1,2,4-triazin-5-yl]-N-hydroxy-
ethanimine oxide (3a). Yield 0.16 g (6%), mp 138–140°C.
IR spectrum, ν, cm–1: 3331, 2981, 1587, 1537, 1463, 1222,
1
1029, 734, 682. H NMR spectrum (DMSO-d6), δ, ppm
(J, Hz): 1.27 (3H, t, J = 6.8, CH3); 3.30 (3H, s, CH3); 4.13
(2H, q, 1J = 6.8, CH2); 7.14–7.26 (2H, m, H Ar); 7.54–7.56
(1H, m, H Ar); 7.76–7.86 (1H, m, H Ar); 9.62 (1H, s,
H triazine). 13C NMR spectrum (DMSO-d6), δ, ppm: 14.5;
25.3; 64.0; 113.7; 120.5; 124.8; 131.5; 132.3; 142.9; 148.3;
157.1; 164.9; 199.2. Mass spectrum, m/z (Irel, %): 274 [M]+
(4), 228 (8), 200 (5), 148 (13), 119 (100), 53 (16).
1
2
CH2); 4.20 (1H, dd, J = 3.6, J = 2.0, CH); 5.00 (1H, p,
J = 5.6, CH); 6.78 (1H, d, J = 1.6, H triazine); 6.98 (1H, t,
J = 8.0, H Ar); 7.08 (1H, d, J = 8.0, H Ar); 7.36–7.44 (2H, m,
H Ar); 10.60 (1H, br. s, NH). 13C NMR spectrum (CDCl3),
δ, ppm: 15.5; 55.3; 82.9; 112.7; 119.8; 121.4; 131.2; 132.4;
134.3; 154.5; 156.9. Mass spectrum (EI, 70 eV) m/z (Irel, %):
276 [M]+ (1), 229 (38), 202 (100), 174 (55), 148 (8), 120
(25), 91 (16), 39 (8).
1-[3-(2-Ethoxyphenyl)-1,2,4-triazin-5-yl]-N-hydroxy-
propanimine oxide (3b). Yield 0.29 g (10%), mp 130–
132°C. IR spectrum, ν, cm–1: 3278, 2956, 1583, 1465,
5-(1-Nitroethyl)-3-phenyl-2,5-dihydro-1,2,4-triazine (4b),
mixture of diastereomers 1.5:1. Yield 0.09 g (40%). Major
diastereomer: Rf 0.70. IR spectrum, ν, cm–1: 3390, 2937,
1602, 1548, 1355, 692. 1H NMR spectrum (CDCl3), δ, ppm
1
1230, 1029, 750. H NMR spectrum (DMSO-d6), δ, ppm
(J, Hz): 1.02 (3H, t, J = 7.6, CH3); 1.34 (3H, t, J = 6.8,
CH3); 2.81 (2H, q, J = 7.6, CH2); 4.15 (2H, q, J = 6.8,
CH2); 7.12 (1H, t, J = 7.6, H Ar); 7.21 (1H, d, J = 8.0,
1
(J, Hz): 1.70 (3H, d, J = 6.8, CH3); 4.31 (1H, dd, J = 6.4,
1
2
H Ar); 7.57 (1H, td, J = 8.0, J = 1.6, H Ar); 7.69 (1H, t,
J = 7.2, H Ar); 9.19 (1H, s, H triazine); 13.30 (1H, s, OH).
13C NMR spectrum (DMSO-d6), δ, ppm: 14.4; 16.2; 30.6;
64.0; 113.4; 120.5; 124.8; 130.7; 131.5; 132.3; 143.2;
156.9; 157.1. Found, m/z: 289.1295 [M–H]. C14H18N4O3.
Calculated, m/z: 289.1217.
2J = 2.4, CH); 4.90 (1H, q, J = 6.8, CH); 6.82 (1H, d,
J = 1.6, H triazine); 7.43–7.51 (4H, m, H Ph); 7.71 (1H, t,
J = 7.2, H Ph); 8.71 (1H, br. s, NH). 13C NMR spectrum
(CDCl3), δ, ppm: 15.3; 55.4; 83.0; 126.5; 128.4; 131.4;
131.8; 132.0; 134.8. Minor diastereomer: Rf 0.62. IR spectrum,
ν, cm–1: 3396, 2933, 1610, 1552, 1356, 700. H NMR
1
1-[3-(2-Ethoxyphenyl)-1,2,4-triazin-5-yl]-N-hydroxy-
butanimine oxide (3c). Yield 0.39 g (13%), mp 85–86°C.
IR spectrum, ν, cm–1: 3315, 2920, 1436, 1234, 1375, 750.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 0.88 (3H, t,
J = 7.2, CH3); 1.34 (3H, t, J = 6.8, CH3); 1.47 (2H, dq,
J = 7.2, CH2); 2.78 (2H, t, J = 7.2, CH2); 4.15 (2H, q,
J = 7.2, CH2); 7.12 (1H, t, J = 7.6, H Ar); 7.21 (1H, d,
J = 8.4, H Ar); 7.57 (1H, td, 1J = 8.4, 2J = 1.6, H Ar); 7.63
spectrum (CDCl3), δ, ppm (J, Hz): 1.77 (3H, d, J = 6.8,
1
2
CH3); 4.22 (1H, dd, J = 6.4, J = 2.4, CH); 4.86 (1H, p,
J = 6.8, CH); 6.77 (1H, d, J = 1.2, H triazine); 7.43–7.51
(4H, m, H Ph); 7.71 (1H, t, J = 7.2, H Ph); 8.71 (1H, br. s,
NH). 13C NMR spectrum (CDCl3), δ, ppm: 15.6; 55.4;
83.2; 126.4; 128.5; 131.4; 131.9; 132.1; 134.8.
3-(Naphthalen-1-yl)-5-(1-nitroethyl)-2,5-dihydro-1,2,4-
triazine (4c), mixture of diastereomers 4:1. Yield 0.16 g
975