Medicinal Chemistry Research (2021) 30:712–728
725
CH=N), 7.58 (2H, d, J = 8.4 Hz), 6.88 (2H, d, J = 8.4 Hz),
Tert-butyl(S,E)-(1-(2-(3,4-dimethoxybenzylidene)
5
.22 (1H, br.s, NH-Boc), 4.22 (1H, br.s, CH–NH), 3.82
hydrazineyl)-4-methyl-1-oxopentan-2-yl)carbamate (10h)
(
1
3H, s, OCH ), 1.82 (1H, m), 1.70 (1H, m), 1.62 (1H, m),
.42 (9H, s), 0.94 (6H, d, J = 6.6 Hz); C-NMR (150 MHz,
3
13
Colorless solid; Yield: 79%; m.p. 99–105 °C; FT-IR (solid,
−
1
CDCl ): δ 21.7, 22.7, 28.3, 42.2, 49.2, 55.3, 79.2, 114.1,
cm ): 2961, 1667, 1602, 1572, 1510, 1460, 1418, 1389,
3
1
1
4.2, 114.3, 126.2, 128.8, 129.4, 144.4, 161.4, 175.2;
1364, 1265, 1237, 1162, 1052; H-NMR (DMSO-d6,
600 MHz): δ 11.12 (1H, s, NH), 7.88 (1H, s, CH=N), 7.28
+
+
HRMS (ESI ) m/z: 364.2227 [M+H] .
(1H, s), 7.00 (1H, d, J = 8.4 Hz), 6.87 (1H, d, J = 8.4 Hz),
Tert-butyl(S,E)-(1-(2-(2,5-dimethoxybenzylidene)
hydrazineyl)-4-methyl-1-oxopentan-2-yl)carbamate (10e)
4.92 (1H, br.s, NH-Boc), 4.01 (1H, dd, J = 8.4, 6.0 Hz,
CH–NH), 4.01 (3H, s, OCH ), 3.78 (3H, s, OCH ), 1.72
3
3
(
1H, m), 1.63 (1H, m), 1.52 (1H, m), 1.36 (9H, s), 0.99 (3H,
1
3
Colorless solid; Yield: 84%; m.p. 88–95 °C; FT-IR (solid,
d, J = 6.6 Hz), 0.88 (3H, d, J = 6.6 Hz);
C-NMR
−
1
cm ): 2959, 1669, 1495, 1462, 1425, 1362, 1253, 1218,
(150 MHz, DMSO): δ 21.7, 22.9, 28.3, 39.4, 40.1, 49.4,
1
1
164, 1111, 1042; H-NMR (DMSO-d , 600 MHz): δ 11.23
52.0, 55.2, 78.0, 107.6, 111.5, 121.5, 127.0, 143.3, 147.0,
6
+
+
(
7
1H, s, NH), 8.28 (1H, s, CH=N), 7.30 (1H, d, J = 1.8 Hz),
.06 (2H, d, J = 8.4 Hz), 4.92 (1H, br.s, NH-Boc), 3.99
1H, br.s, CH–NH), 3.99 (3H, s, OCH ), 3.79 (3H, s,
149.0, 155.4, 174.1; HRMS (ESI ) m/z: 394.1983 [M+H] .
(
Tert-butyl(S,E)-(1-(2-(4-chlorobenzylidene)hydrazineyl)-4-
3
OCH ), 1.71 (1H, m), 1.61 (1H, m), 1.50 (1H, m), 1.44 (9H,
s), 0.96 (6H, d, J = 6.6 Hz); C-NMR (150 MHz, DMSO):
δ 21.2, 22.9, 28.2, 39.5, 40.1, 49.4, 52.0, 55.3, 78.0, 108.5,
methyl-1-oxopentan-2-yl)carbamate (10i)
3
13
Colorless solid; Yield: 85%; m.p. 151–155 °C; FT-IR (solid,
−1
1
13.4, 117.5, 122.8, 138.7, 142.1, 152.1, 155.6, 174.3;
cm ): 2958, 1667, 1523, 1489, 1458, 1392, 1366, 1319,
+
+
1
HRMS (ESI ) m/z: 394.2340 [M+H] .
1279, 1236, 1091, 1054, 1012; H-NMR (600 MHz, DMSO-
d6): δ 11.30 (1H, s, NH), 7.96 (1H, s, CH=N), 7.70 (2H, dd,
J = 8.4 Hz), 7.50 (2H, dd, J = 8.4 Hz), 6.87 (1H, d, J =
8.4 Hz), 4.93 (1H, br.s, NH-Boc), 4.02 (1H, dd, J = 8.4,
Tert-butyl(S,E)-(1-(2-(2,4-dihydroxybenzylidene)
hydrazineyl)-4-methyl-1-oxopentan-2-yl)carbamate (10f)
5.4 Hz, CH–NH), 1.70 (1H, m), 1.61 (1H, m), 1.50 (1H, m),
Dark brown solid powder; Yield: 82%; m.p. 101–110 °C;
1.36 (9H, s), 0.94 (3H, d, J = 6.6 Hz), 0.88 (3H, d, J =
−
1
13
FT-IR (solid, cm ): 2966, 1667, 1622, 1511, 1457, 1366,
6.6 Hz); C-NMR (150 MHz, DMSO-d ): δ 21.3, 22.9, 28.3,
6
1
1
8
321, 1235, 1162; 1H-NMR (DMSO-d , 600 MHz): δ
1.22 (1H, s, NH), 8.28 (1H, s, CH=N), 7.24 (1H, d, J =
.4 Hz), 7.05 (1H, d, J = 8.4 Hz), 6.30 (1H, s), 4.83 (1H,
39.5, 40.1, 49.3, 52.0, 79.2, 128.2, 128.9, 133.2, 134.3, 142.0,
6
+
35
145.5, 155.5, 174.4; HRMS (ESI ) m/z: 390.1563 (Cl ),
392.1540 (Cl ) [M+Na] .
3
7
+
br.s, NH-Boc), 4.00 (1H, br.s, CH–NH), 1.69 (1H, m),
1
6
3
1
3
.61 (1H, m), 1.52 (1H, m), 1.36 (9H, s), 0.91 (6H, d, J =
.6 Hz); C-NMR (150 MHz, DMSO): δ 21.2, 24.3, 28.2,
Tert-butyl(S, E)-(4-methyl-1-(2-(2-nitrobenzylidene)
hydrazineyl)-1-oxopentan-2-yl)carbamate (10j)
1
3
9.5, 51.8, 78.0, 102.5, 107.7, 110.3, 127.9, 131.2, 142.2,
+
48.4, 155.4, 158.2, 160.6, 168.6; HRMS (ESI ) m/z:
Light yellow powder; Yield: 80%; m.p. 164–168 °C; FT-IR
+
−1
66.1768 [M+H] .
(solid, cm ): 2973, 1668, 1521, 1339, 1260, 1220, 1169,
1
1
056; H-NMR (600 MHz, DMSO-d ): δ 8.38 (1H, s, NH),
6
Tert-butyl(S,E)-(1-(2-(4-hydroxybenzylidene)hydrazineyl)-4-
methyl-1-oxopentan-2-yl)carbamate (10g)
8.67 (1H, s, CH=N), 8.06 (2H, t, J = 8.4 Hz), 7.80 (1H, t,
J = 7.8, 7.2 Hz), 7.66 (1H, dd, J = 7.2 Hz), 4.91 (1H, br.s,
NH-Boc), 4.03 (1H, dd, J = 8.4, 6.0 Hz, CH–NH), 1.71 (1H,
m), 1.63 (1H, m), 1.54 (1H, m), 1.37 (9H, s), 0.92 (3H, d,
Light brown amorphous powder; Yield: 89%; m.p.
−
1
13
1
1
6
05–112 °C; FT-IR (solid, cm ): 2965, 1661, 1604, 1511,
J = 6.6 Hz), 0.87 (3H, d, J = 6.6 Hz); C-NMR (150 MHz,
1
444, 1366, 1239, 1161, 1055, 1022; H-NMR (DMSO-d ,
00 MHz): δ 11.26 (1H, s, NH), 7.85 (1H, s, CH=N), 7.49
DMSO-d ): δ 21.2, 24.3, 28.2, 39.7, 49.4, 52.1, 78.1, 124.7,
6
6
127.4, 128.6, 130.5, 133.6, 138.6, 142.1, 148.2, 155.5,
+
+
(
2H, d, J = 8.4 Hz), 6.84 (2H, d, J = 8.4 Hz), 4.92 (1H, br.s,
174.7; HRMS (ESI ) m/z: 401.1812 [M+Na] .
NH-Boc), 4.00 (1H, t, J = 8.4, 5.4 Hz, CH–NH), 1.71 (1H,
m), 1.61 (1H, m), 1.51 (1H, m), 1.44 (9H, s), 0.95 ((3H, d,
J = 6.6 Hz), 0.88 (3H, d, J = 6.6 Hz); C-NMR (150 MHz,
DMSO): δ 21.7, 22.9, 28.3, 39.4, 40.1, 49.3, 51.9, 78.0,
Tert-butyl(S,E)-(4-methyl-1-(2-(4-nitrobenzylidene)
hydrazineyl)-1-oxopentan-2-yl)carbamate (10k)
13
1
1
15.7, 125.1, 128.3, 143.5, 147.2, 155.4, 159.5, 159.5,
74.0; HRMS (ESI ) m/z: 350.2070 [M+H] .
Light yellow powder; Yield: 82%; m.p. 153–158 °C; FT-IR
(solid, cm ): 2973, 1668, 1521, 1339, 1260, 1220, 1169,
+
+
−1