Paper
NJC
4.3. Preparation of the Fe3O4@SiO2 core–shell26
ArH); 13C NMR (100 MHz, DMSO-d6): dppm 26.8, 28.2, 31.8, 35.3,
49.9, 57.6, 112.0, 119.4, 125.9, 126.6, 127.0, 130.3, 132.9, 147.2,
158.4, 158.5, 195.7.
The synthesized Fe3O4 (2 g) were suspended in distilled water
(40 mL) and sonicated for 20 min. Ethanol (16 mL), ammonia
(5 mL), and tetraethyl orthosilicate (7 mL) were, respectively,
added into the suspension, and continuously reacted for 12 h
under stirring at room temperature. The iron oxide nano-
particles with a thin layer of silica (Fe3O4@SiO2) were separated
by using an external magnet, washed three times with ethanol
and water, and dried under vacuum.
2-Amino-4-(3-ethoxy-4-hydroxyphenyl)-7,7-dimethyl-5-oxo-5,6,7,8-
tetrahydro-4H-chromene-3-carbonitrile (Table 3, entry 6). White
solid; M.p: 218–220 1C; yield: 95%; IR (KBr): n 3473, 3382,
1
3354, 3215, 2195, 1687, 1604, 1372 cmÀ1; H NMR (300 MHz,
DMSO-d6): dppm 1.02 (s, 6H, –CH3), 2.12 (d, 2H, J = 7.1 Hz, –CH2),
2.27 (d, 2H, J = 9.9 Hz, –CH2), 2.51 (t, 3H, J = 5.0 Hz, –CH3), 3.34
(q, 2H, J = 8.0 Hz, –CH2), 4.28 (s, 2H, –CH aliphatic and –OH),
5.17 (s, 2H, –NH2), 7.15 (s, 1H, ArH), 7.36 (d, 1H, J = 5.4 Hz, ArH),
7.75 (d, 1H, J = 5.6 Hz, ArH); 13C NMR (75 MHz, DMSO-d6): dppm
27.0, 28.3, 31.9, 35.8, 49.9, 57.1, 109.5, 111.7, 118.8, 128.4, 132.5,
150.3, 158.5, 163.1, 195.8.
4.4. General procedure for the synthesis of ACoPc27
Ammonium molybdate (0.01 mg) was added to a solution of
3-nitrophthalic anhydride (1.93 g, 10 mmol), urea (3.0 g,
50 mmol), and CoSO4Á7H2O (0.47 mg, 2.6 mmol) in nitro-
benzene (15 mL). The mixture was stirred under N2 at 200 1C.
After 4 h, the reaction mixture was cooled and diluted with
toluene (80 mL). The resulting purple precipitate was collected
by centrifugation. The solid was washed with toluene, water,
MeOH/ether (1 : 9), and EtOAc/hexane (2 : 1), and dried to afford
a dark green solid (2.56 g, 99%). After that, sodium sulfide
nonahydrate (7.4 g, 30.9 mmol) was added to tetranitro cobalt
phthalocyanine (1.95 g, 2.57 mmol) in DMF (50 mL) and stirred
at 70 1C for 4 h. After completion of the reaction, the mixture
was cooled and collected by centrifugation. The product was
washed by addition of methanol/ether (1 : 9) and methanol and
washed two times with ethanol followed by centrifugation. The
mixture was dried to obtain a green solid.
2-Amino-4-(2-hydroxy-3-methoxyphenyl)-7,7-dimethyl-5-oxo-
5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (Table 3, entry 7).
Orange solid; M.p: 181–183 1C; yield: 92%; IR (KBr): n 3562,
1
3391, 3348, 2954, 2290, 1590, 1482 cmÀ1; H NMR (400 MHz,
DMSO-d6): dppm 3.12 (s, 3H, –CH3), 3.40 (s, 3H, –CH3), 3.47 (s,
3H, –CH3), 3.56 (s, 2H, –NH2), 3.66 (s, 1H, –OH), 3.79 (d, 2H,
J = 4.4 Hz, –CH2), 3.90 (d, 2H, J = 4.0 Hz, –CH2), 5.18 (s, 1H, –CH
aliphatic), 6.53 (t, 1H, J = 7.8 Hz, ArH), 6.73 (d, 1H, J = 8.4 Hz,
ArH), 6.84 (d, 1H, J = 4.8 Hz, ArH); 13C NMR (100 MHz, DMSO-
d6): dppm 27.9, 43.0, 55.3, 60.3, 61.9, 62.0, 72.7, 123.3, 138.3, 147.9,
150.9, 158.5, 164.4, 166.5, 168.5, 182.1, 183.2, 183.3, 196.1.
2-Amino-4-(2,5-dimethoxyphenyl)-7,7-dimethyl-5-oxo-5,6,7,8-
tetrahydro-4H-chromene-3-carbonitrile (Table 3, entry 8). Cream
solid; M.p: 181–183 1C; yield: 95%; IR (KBr): n 3391, 3334, 3216,
1
2951, 2193, 1682, 1650, 1499, 1374 cmÀ1; H NMR (300 MHz,
4.5. Preparation of ACoPc-MNPs
DMSO-d6): dppm 1.03 (s, 6H, –CH3), 2.08 (d, 2H, J = 7.2 Hz, –CH2),
2.27 (d, 2H, J = 7.1 Hz, –CH2), 3.69 (s, 6H, –CH3), 4.42 (s, 1H, –CH
aliphatic), 5.17 (s, 2H, –NH2), 6.50 (s, 1H, ArH), 6.73 (d, 1H,
J = 5.8 Hz, ArH), 6.89 (d, 1H, J = 6.0 Hz, ArH); 13C NMR (75 MHz,
DMSO-d6): dppm 26.5, 28.7, 31.8, 50.0, 55.2, 56.3, 57.2, 111.5, 111.8,
112.6, 114.8, 119.8, 133.5, 151.0, 153.1, 158.9, 163.2, 195.6.
Fe3O4@SiO2 (1.55 g), ACoPc (1.88 g) and CPTMS (7.4 g) were
suspended in dried toluene and refluxed for 24 h under stirring
at 110 1C. The product was separated by means of an external
magnet, washed three times with toluene and dried in air to
obtain a brown solid.
4.6. General procedure for the synthesis of
tetrahydrobenzo[b]pyran derivatives
Acknowledgements
A solution of dimedone (0.066 g, 1 mmol), aromatic aldehydes
(1 mmol), malononitrile (0.14 g, 1 mmol) and ACoPc-MNPs
(0.02 g) was stirred at room temperature for the required time
(Table 2). After completion of the reaction, as monitored by
TLC, ethanol was added to the reaction mixture, and the
catalyst was easily collected by means of a magnet to be reused
in subsequent reactions. The obtained products were recrystallized
in ethanol and characterized by 1H NMR, IR and 13C NMR.
We thank Bu-Ali Sina University and Iran National Science
Foundation (INSF) for financial support (The Grant of Allameh
Tabataba ‘i’s Award, Grant Number: BN093) to our research group.
Notes and references
1 See reviews: (a) B. Karimi, F. Mansouri and H. M. Mirzaei,
ChemCatChem, 2015, 7, 1736; (b) T. Cheng, D. Zhang, H. Li and
G. Liu, Green Chem., 2014, 16, 3401; (c) M. B. Gawande, R. Luque
and R. Zboril, ChemCatChem, 2014, 6, 3312; (d) D. Zhang,
C. Zhou, Z. Sun, L. Wu, C. Tunga and T. Zhang, Nanoscale,
2012, 4, 6244.
2 H. Uchida, P. Y. Reddy, S. Nakamura and T. Toru, J. Org.
Chem., 2003, 68, 8736.
3 (a) S. L. Jain, J. K. Joseph, S. Singhal and B. Sain, J. Mol.
Catal. A: Chem., 2007, 268, 134; (b) V. B. Sharma, S. L. Jain
and B. Sain, Tetrahedron Lett., 2003, 44, 383; (c) C. Perollier
4.7. Some selected spectral data of the new products
2-Amino-4-(2-hydroxyphenyl)-7,7-dimethyl-5-oxo-5,6,7,8-tetra-
hydro-4H-chromene-3-carbonitrile (Table 3, entry 5). Yellow
solid; M.p: 247–249 1C; yield: 92%; IR (KBr): n 3439, 3386,
1
2955, 2207, 1659, 1627, 1383 cmÀ1; H NMR (400 MHz, DMSO-
d6): dppm 0.96 (s, 3H, –CH3), 1.04 (s, 3H, –CH3), 2.15 (d, 2H, J =
8.0 Hz, –CH2), 2.28 (d, 2H, J = 8.2 Hz, –CH2), 2.53 (s, 1H, –OH),
4.22 (s, 1H, –CH aliphatic), 7.13 (t, 1H, J = 6.2 Hz, ArH), 7.17 (s,
2H, –NH2), 7.27 (d, 2H, J = 8.0 Hz, ArH), 7.36 (t, 1H, J = 7.6 Hz,
New J. Chem.
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