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(C=O), 157.9 (C=O), 162.7 (quart. ArC), 165.0 (COH) ppm; IR: 1660 (C=O), 1613 (C=O) cm-1; Anal.
calcd. for C14H15NO5: C, 60.64; H, 5.45; N, 5.05. Found: C, 60.61; H, 5.40; N, 4.99.
Syntheses of 5-(4-methoxyphenyl)-1-methylpyrrolidine-2,3-dione (2b)
2,3-Dioxopyrrolidine (1b, 3.38 g, 11.53 mmol) was dispersed in a 10% HCl solution (130 mL) and
heated under reflux for 7 hours, during which it dissolved gradually to give a yellowish solution. The
reaction mixture was then cooled and left standing overnight. Compound 2b slowly precipitated out as
a yellow solid, which was filtered, washed with water (5 mLx3) and ether (5 mLx3). After drying
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under reduced pressure 2b was obtained (1.73 g, 68%), m.p. 156-157 °C; H-NMR: δ 2.56 (dd, J = 7.5
Hz, 1H, CHa), 2.89 (s, 3H, NCH3), 3.13 (dd, J = 7.5 Hz, 1H, CHb), 3.81 (s, 3H, OCH3), 4.74 (d, J = 9
Hz, 2H, NCH3CHAr), 6.92 (d, J = 9 Hz, 2H, ArH), 7.11 (d, J = 6 Hz, 2H, ArH) ppm; 13C-NMR: δ 29.7
(NCH3), 41.1 (CH2), 55.6 (OCH3), 58.1 (CH), 109.9 (quart. ArC), 115.1 (ArCH), 127.9 (ArCH), 130.3
(C=O), 160.3 (quart. ArC), 198.3 (C=O) ppm; IR: 1749 (C=O), 1702 (C=O) cm-1; Anal. calcd. for
C12H13NO3: C, 65.74; H, 5.98; N, 6.39. Found: C, 65.70; H, 5.91; N, 6.43.
General procedures for the syntheses of hydrazone derivatives
Equimolar quantities (0.01 mol) of 5-(4-methoxyphenyl)-1-methylpyrrolidine-2,3-dione (2b) and
the corresponding hydrazine salts were dissolved in warm ethanol. The reaction mixture was refluxed
for 3 hours and then kept at room temperature overnight. The resulting solid was washed with ethanol
and dried under reduced pressure to afford compounds 3a-c (for 3d the solvent of the product was
removed under reduced pressure before being washed with ether).
(3E)-3-[2-(2,4-dinitrophenyl)hydrazinylidene]-5-(4-methoxyphenyl)-1-methylpyrrolidin-2-one
(3a):
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from 2b, yield 65%, m.p 206-207 °C; H-NMR: δ 2.79 (s, 3H, NCH3), 2.86 (dd, J = 7.5 Hz, 1H, CHa),
3.39 (dd, J = 7.5 Hz, 1H, CHb), 3.82 (s, 3H, OCH3), 4.70 (dd, J = 3 Hz, 1H, NCH3CHAr), 6.92 (d, J =
9 Hz, 2H, ArH), 7.15 (d, J = 9 Hz, 2H, ArH), 8.01 (d, J = 9 Hz, 1H, ArH), 8.29 (dd, J = 1.5 Hz, 1H,
ArH), 9.11 (dd, J = 3 Hz, 1H, ArH), 10.94 (s br, 1H, NH) ppm; 13C-NMR: δ 28.6 (NCH3), 35.2 (CH2),
55.6 (OCH3), 60.9 (CH), 115.0 (ArCH), 115.9 (quart. ArC), 123.5 (ArCH), 127.9 (ArCH), 129.7
(ArCH), 141.0 (quart. ArC), 144.1 (quart. ArC), 144.7 (quart. ArC), 160.0 (quart. C=N), 160.3 (quart.
ArC), 163.0 (C=O); IR: 3315 (NH), 1702 (C=O) cm-1; Anal. calcd. for C18H17N5O6: C, 54.14; H,
4.29; N, 17.54. Found: C, 54.05; H, 4.35; N, 17.60.
4-{(2E)-2-[5-(4-methoxyphenyl)-1-methyl-2-oxopyrrolidin-3-ylidene]hydrazinyl}benzohydrazide (3b):
1
from 2b, yield 55%, m.p 204-205 °C; H-NMR: δ 2.61 (s, 3H, NCH3), 2.86 (dd, J = 7.5 Hz, 1H, CHa),
3.32 (dd, J = 7.5 Hz, 1H, CHb), 3.73 (s, 3H, OCH3), 4.32 (s br, 2H, NH2), 4.69 (d, J = 6 Hz, 1H,
NCH3CHAr), 6.93 (d, J = 9 Hz, 2H, ArH), 7.15 (d, J = 9 Hz, 2H, ArH), 7.25 (d, J = 9 Hz, 1H, ArH),
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8.08 (d, J = 9 Hz, 1H, ArH), 8.61 (s, 1H, ArH), 9.66 (s br, 1H, NH), 10.49 (s br, 1H, NH) ppm; C-
NMR: δ 28.9 (NCH3), 33.2 (CH2), 55.8 (OCH3), 59.1 (CH), 107.9 (quart. ArC), 115.1 (ArCH), 121.9
(quart. ArC), 128.5 (ArCH), 133.4 (ArCH), 137.6 (ArCH), 142.6 (ArCH), 148.0 (quart. ArC), 159.2
(quart. C=N), 159.7 (quart. ArC), 164.6 (C=O), 165.3 (C=O); IR: 3211 (NH), 1688 (C=O), 1601