TABLE 2. Data of IR and Mass Spectra of the Synthesized Compounds
Com-
pound
Mass spectrum,
IR spectrum, ν, cm-1
m/z [M]+·
2а
2b
3а
3b
5а
5b
7b
8а
3388, 1723, 1685, 1624, 1453, 1288, 1203, 736
3246, 1713, 1509, 1342, 1298, 1211, 1159, 1057, 834, 746
3195, 1726, 1678, 1501, 1479, 1447, 1366, 1269, 1232, 827, 763
3211, 1700, 1507, 1482, 1375, 1264, 1213, 846
3226, 1711, 1506, 1432, 1364, 1217, 757
—
—
209.3
209.3
225.3
225.3
278.3
224.3
3186, 1701, 1502, 1368, 1280, 1213, 1151, 844, 822
1696, 1641, 1550, 1510, 1198, 1180, 1079, 856
3074, 2905, 1724, 1653, 1605, 1508, 1429, 1289, 1273, 1223, 819,
758, 672
8b
3091, 2927, 1741, 1634, 1510, 1410, 1322, 1220, 1197, 838
3434, 2706, 1701, 1506, 1461, 1416, 1227, 820, 766, 756, 749
3052, 2749, 1691, 1513, 1433, 1337, 1237, 833, 747
1737, 1700, 1511, 1396, 1281, 1226, 1132, 840, 817
3308, 3281, 1680, 1636, 1510, 1402, 1319, 1240, 1232, 1126, 831
3246, 1669, 1654, 1609, 1512, 1254, 1240, 1032, 829
3122, 1680, 1665, 1512, 1404, 1323, 1231, 827
224.3
296.3
296.3
238.3
238.3
356.3
344.34
406.1
369.3
302.3
9а
9b
10b
11b
12b
13b
14b
15b
16b
3130, 1666, 1662, 1511, 1405, 1396, 1235, 830, 815
3222, 2891, 1674, 1612, 1600, 1507, 1270, 1224, 1180, 844
1719, 1585, 1511, 1485, 1392, 1377, 1328, 1227, 964, 829, 764
proton signals of which have different intensities. As a result of stronger shielding the signals of the protons of
the Z-isomers are observed at higher field [3]. On the basis of the intensities of the signals of the NH group
proton it is concluded that in DMSO-d6 solution the Z-isomer always predominates.
The interaction of 1-(4-fluorophenyl)-4-hydrazinocarbonyl-2-pyrrolidinone (11b) with acetylacetone led
to the synthesis of 4-(3,5-dimethyl-1-pyrazolylcarbonyl)-1-(4-fluorophenyl)-2-pyrrolidinone (16b). In the
1H NMR spectrum of compound 16b (Table 1), apart from the signals of the protons of the aromatic and
pyrrolidone rings, a characteristic signal is observed for the CH=C fragment of the pyrazole ring at 6.0, and also
signals of the two methyl groups at 2.24 and 2.55 ppm.
EXPERIMENTAL
1
The H NMR spectra were obtained on a Jeol FX 100 (100 MHz) spectrometer, internal standard was
TMS. The IR spectra were recorded on a Perkin-Elmer FT-IR instrument in KBr disks, and the mass spectra on a
Waters ZQ 2000 spectrometer, chemical ionization, ionizing voltage 15 eV.
A check on the progress of reactions and the purity of the compounds obtained was effected by TLC on
Silufol UV-254 plates, visualization was in UV light or with iodine vapor.
N-(2-Fluorophenyl)-β-alanine (2a). A mixture of 2-fluoroaniline 1a (11.1 g, 0.1 mol), acrylic acid
(7.2 g, 0.1 mol), and 20% acetic acid (60 ml) was boiled for 8 h, cooled, the crystals of compound 2a which had
separated were filtered off, and crystallized from acetone–hexane, 1:1.
N-(4-Fluorophenyl)-β-alanine (2b). A mixture of 4-fluoroaniline 1b (11.1 g, 0.1 mol), acrylic acid
(7.2 g, 0.1 mol), and 20% acetic acid (60 ml) was boiled for 8 h, cooled, 25% NaOH (50 ml) was added, and the
unreacted 4-fluoroaniline was extracted with ether (2 × 100 ml). The extract was acidified with 10%
hydrochloric acid to pH 7, the crystals of 2b, which separated on standing, were filtered off, washed with water,
dried, and crystallized from acetone–hexane, 1:1.
758