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tion of the reaction as monitored by thin-layer chromatography.
Within the flask, the catalyst was separated by using a magnet and
the crude solution was decanted followed by evaporation of acetic
acid on a rotavapor. Then, the desired solid product 2-cyanoacryla-
mide 1 was purified by washing the crude solid with diethyl ether
(3ꢂ15 mL) in which nonpolar impurities dissolved. Finally, all the
products were purified by recrystallization in methanol.
Figure 6. Catalyst recovery by using a magnet, A) reaction mixture with
catalyst, B) catalyst separation.
Spectroscopic data of selected compounds
All product data were compared with the reported literature
data.[12,13]
(E)-3-(4-Chlorophenyl)-2-cyanoacrylamide (1a): White solid; IR
(ATR): n˜max =3153.45, 2215.03, 1701.38, 1587.68, 1487.92, 1380.93,
1208, 1093.87, 1033.17, 1010.04, 957.38, 826.04, 811.25, 785.91,
1
707.36 cmÀ1; H NMR ([D6]DMSO, 200 MHz): d=8.18 (s, 1H), 7.89–
7.99 (m, 4H), 7.82 (br. s., 1H), 7.65 ppm (d, J=8.6 Hz, 2H); 13C NMR
([D6]DMSO, 50 MHz): d=162.5, 149.2, 136.9, 131.7, 129.7, 129.4,
116.2, 107.3 ppm.
(E)-2-Cyano-3-(3, 4-dimethoxyphenyl) acrylamide (1 f): Brown solid;
IR (ATR): n˜max =3393.38, 3158.79, 2214.32, 1692.35, 1630.34,
1582.72, 1571.33, 1509.12, 1465.61, 1441.89, 1420.75, 1377.42,
1331.01, 1266.03, 1244, 1198.6, 1165.06, 1142.56, 1033.67, 1021.77,
1011.63, 950.61, 849.05, 799.7, 777.95, 733.01, 676.62, 627.84 cmÀ1
;
1H NMR ([D6]DMSO, 200 MHz): d=8.11 (s, 1H), 7.79 (br. s., 1H), 7.67
(d, J=1.9 Hz, 2H), 7.57 (dd, J=8.5, 1.9 Hz, 1H), 7.15 (d, J=8.5 Hz,
1H), 3.86 (s, 3H), 3.80 ppm (s, 3H); 13C NMR ([D6]DMSO, 50 MHz):
d=163.1, 152.5, 150.6, 148.7, 125.5, 124.5, 117.2, 112.2, 111.8, 102.8,
55.8, 55.5 ppm.
Figure 7. Catalyst recycle study of Fe3O4/PVP–PWA (141) for the synthesis of
1a. Reaction conditions: 2a or 5a, 1 mmol; 3, 1.1 mmol; Fe3O4/PVP–PWA
(141), 0.1 g; T=1208C; 10 mL AcOH:H2O(2%), t=6 h; isolated yields after
work-up.
(E)-2-Cyano-3-(3-nitrophenyl)acrylamide (1g): Yellowish solid; IR
(ATR): n˜max =2923.41, 2210.50, 1702.48, 1604.34, 1526.23, 1349.38,
1054.42, 1033.25, 823.97, 733.07 cmÀ1
;
1H NMR ([D6]DMSO,
N2 up to 9008C with the heating rate of 108C/minute. ICP–OES
200 MHz): d=8.77 (s, 1H), 8.25–8.44 (m, 3H), 8.02 (br. s., 1H), 7.78–
7.95 ppm (m, 2H); 13C NMR ([D6]DMSO, 50 MHz): d=162.1, 148.3,
148.0, 135.9, 133.5, 130.8, 126.2, 124.1, 115.8, 109.5 ppm.
was conducted on Thermo Fisher instrument.
General procedure for the preparation of catalyst Fe3O4/
PVP–PWA
(E)-3-(Benzo[d][1,3]dioxol-5-yl)-2-cyanoacrylamide (1k): White solid;
IR (ATR): n˜max =3393.38, 3158.79, 2214.32, 1692.35, 1571.23,
1509.10, 1463.60, 1439.49, 1419.71, 1331.01, 1238, 1198.5, 1165.16,
1141.56, 1032.68, 1021.67, 1011.65, 950.51, 849.15, 799.17, 776.95,
Magnetically separable composite, Fe3O4/PVP–PWA, was prepared
by quaternization method by varying the ratios of Fe3O4, PVP, and
PWA as 1:4:1, 1:3:1, 1:8:1, and were designated as Fe3O4/PVP–PWA
(131) or Fe3O4/PVP–PWA (141) and Fe3O4/PVP–PWA (181).
1
731.03, 666.62, 626.83 cmÀ1; H NMR ([D6]DMSO, 200 MHz): d=8.08
(s, 1H), 7.81 (br. s., 1H), 7.70 (br. s., 1H), 7.59 (s, 1H), 7.48 (d,
J=8.3 Hz, 1H), 7.12 (d, J=8.1 Hz, 1H), 6.17 ppm (s, 2H); 13C NMR
([D6]DMSO,50 MHz): d=162.9, 151.0, 150.2, 148.1, 128.0, 126.0,
117.0, 109.0, 108.0, 103.4, 102.3 ppm.
In a typical procedure, respective amounts of PVP (0.333/0.444/
0.888 g, 3/4/8 mmol) were taken in a 250 mL round-bottom flask.
To this, solution of PWA (2.880 g, 1 mmol) in distilled water (30 mL)
was added dropwise with stirring using an addition funnel for
15 min. Simultaneously, Fe3O4 (0.231 g, 1 mmol) was added and
the mixture was stirred for 12 h at RT to obtain a brown color pre-
cipitate. Water was removed from the mixture on a rotavapor kept
at 808C for 2 h. Finally, brown powdered catalyst was yielded in
95% yield, which was then dried at 1008C for 6 h.
(2E,4E)-2-Cyano-5-phenylpenta-2,4-dienamide (1m): Brown solid; IR
(ATR): n˜max =2973.46, 2217.40, 1680.52, 1577.22, 1368.71, 1054.59,
1
1033.22, 999.91, 750.1, 686.36 cmÀ1; H NMR ([D6]DMSO, 200 MHz):
d=7.98 (d, J=11.1 Hz, 1H), 7.84 (br. s., 1H), 7.60–7.76 (m, 3H),
7.37–7.54 (m, 4H), 7.07–7.27 ppm (m, 1H); 13C NMR (chloroform-d,
50 MHz): d=162.5, 151.3, 146.8, 134.9, 130.6, 129.1, 128.2, 123.0,
115.4, 107.8 ppm.
(E)-2-Cyano-3-(naphthalen-1-yl) acrylamide (1o): Brown solid; IR
(ATR): n˜max =3403.83, 3168.7, 2222.63, 1696.08, 1591.26, 1381.73,
1352.39, 1243.98, 1033.27, 946.38, 807.86, 784.86, 768.74, 728.44,
General procedure for the synthesis of 2-cyanoacrylamides
(1)
1
670.29, 632.01 cmÀ1; H NMR ([D6]DMSO, 200 MHz): d=8.88 (s, 1H),
To the solution of aldehyde (2) or acetal (5, 1 mmol) and malononi-
trile (3, 1.1 mmol) in 25 mL flask containing 10 mL acetic acid and
water (2–50% as per requirement), catalyst Fe3O4/PVP–PWA (0.1 g)
was added. Then, the solution was heated at reflux until comple-
8.11–8.27 (m, 4H), 8.07 (d, J=7.1 Hz, 3H), 7.89 (br. s., 1H), 7.62–
7.73 ppm (m, 4H); 13C NMR ([D6]DMSO, 50 MHz): d=162.7, 148.6,
133.1, 132.0, 130.8, 129.4, 128.9, 127.6, 127.3, 126.9, 125.5, 123.7,
116.2, 111.2 ppm.
ChemCatChem 2016, 8, 1 – 11
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