JOURNAL OF CHEMICAL RESEARCH 2016 33
(7b): White powder; m.p. 235–237 oC; IR (KBr) (νmax/cm-1): 3450,
3300, 3200, 3060, 2975, 2900, 1620, 1590,1560,1440, 1380, 1085, 840;
1H NMR (400 MHz, DMSO-d6): δ 1.19 (6H, s, 2CH2CH3), 2.55 (3H,
s, SCH3), 4.47 (4H, br. s, 2CH2CH3), 5.51 (1H, s, ArH), 7.13 (2H, d,
J=8.0 Hz, ArH), 7.30 (2H, d, J=8.0 Hz, ArH), 7.59 (1H, br. s, NH),
16.74 (1H, s, CO–NH) ppm; 13C NMR (100 MHz, DMSO-d6): δ 12.5,
12.9, 13.3, 34.3, 43.7, 95.5, 96.1, 128.4, 128.8, 128.8, 128.9,130.0, 130.8,
138.2, 160.6, 161.2, 164.3, 174.8 ppm. Anal. calcd for C20H20ClN5O2S2
(461.99): C, 52.00; H, 4.36; N, 15.16; found: C, 52.15; H, 4.48; N,
15.01%.
White powder; m.p. 225–227 C; IR (KBr) (νmax/cm-1) (KBr): 3400,
o
3300, 3200, 3066, 2960, 2900, 1620, 1560, 1480, 1450, 1370, 1260,
1040, 870, 780, 700; H NMR (400 MHz, DMSO-d6):δ 1.20 (6H, br.
1
s, 2CH2CH3), 2.56 (3H, s, SCH3), 3.69 (3H, s, OCH3), 4.48 (4H, br. s,
CH2CH3), 5.50 (1H, s, CH), 6.61 (1H, s, ArH), 6.68 (1H, d, J=7.6 Hz,
ArH), 6.77 (1H, dd, J=8.4 Hz, 2.4 Hz, ArH),7.19 (1H, t, J=7.6 Hz,
ArH), 7.55 (1H, br. s, NH), 16.81 (1H, br. s, NH–CO) ppm; 13C NMR
(100 MHz, DMSO-d6): δ 12.5, 12.9, 13.3, 34.6, 41.4, 43.7, 56.5, 95.5,
96.5, 111.0, 113.2, 119.2, 129.6, 159.6, 159.7, 160.5, 161.6, 162.0, 164.0,
164.3, 174.7 ppm. Anal. calcd for C21H23N5O3S2 (457.57): C, 55.12; H,
5.07; N, 15.31; found: C, 55.01; H, 5.18; N, 15.12%.
1,3-Diethyl-8-(ethylthio)-5-(4-nitrophenyl)-2-thioxo-2,3,7,10-
tetrahydropyrido[2,3-d:6,5-d’]dipyrimidine-4,6(1H,5H)-dione
(7i): White powder; m.p. 230–232 oC; IR (KBr) (νmax/cm-1): 3420,
3300, 3200, 3050, 2990, 2910, 1620, 1560, 1500, 1440, 1380, 1500,
1,3-Diethyl-8-(methylthio)-5-(3-nitrophenyl)-2-thioxo-2,3,7,10-
tetrahydropyrido[2,3-d:6,5-d’]dipyrimidine-4,6(1H,5H)-dione (7c):
o
White powder; m.p. 233–235 C; IR (KBr) (νmax/cm-1): 3460, 3350,
3200 ,3100, 2990, 2900,1615, 1580, 1560, 1430, 1380, 1520,1340, 850,
1
780, 685; H NMR (400 MHz, DMSO-d6): δ 1.20 (6H, s, 2CH2CH3),
2.57 (3H, s, SCH3), 4.49 (4H, m, 2CH2CH3), 5.65 (1H, s, CH),
7.50–7.64 (3H, m, ArH), 7.88 (1H, s, NH), 8.08 (1H, d, J=6.4 Hz, ArH),
16.72 (1H, br. s, CO–NH) ppm; 13C NMR (100 MHz, DMSO-d6):
δ 12.6, 13.3, 34.7, 43.7, 95.0, 95.6, 121.5, 121.6, 129.9, 130.1, 134.3,
141.8, 148.3, 160.9, 164.3, 174.9 ppm. Anal. calcd for C20H20N6O4S2
( 472.54): C, 50.83; H, 4.27; N, 17.78; found: C, 50.61; H, 4.13; N,
17.54%.
1
1340, 840; H NMR (400 MHz, DMSO-d6):δ 1.20 (6H, t, J=6.4 Hz,
2CH2CH3), 1.35 (3H, t, J = 7.2 Hz, SCH2CH3), 3.19 (2H, m, SCH2CH3),
4.47 (4H, q, J=6.4 Hz, 2CH2CH3), 5.64 (1H, s, CH), 7.42 (2H, d, J=8.4
Hz, ArH), 7.63 (1H, br. s, NH), 8.13 (2H, d, J=8.4 Hz, ArH), 16.67 (1H,
s, NHCO) ppm; 13C NMR (100 MHz, DMSO-d6):δ 12.6, 15.0, 24.9,
35.1, 43.7, 95.3, 95.7, 123.7, 128.5, 146.2, 148.0, 160.3, 161.8, 163.9,
164.0, 164.4, 174.9 ppm. Anal. calcd for C21H22N6O4S2 (486.57): C,
51.84; H, 4.56; N, 17.27; found: C, 51.60; H, 4.32; N, 17.02%.
5- (2,4-Dichlorophenyl)-1,3-diethyl-8- (ethylthio)-2-thioxo-
2 , 3,7,10 -tetrahydropyrido [2 , 3- d : 6 , 5- d’] dipyrimidine-
4,6(1H,5H)-dione (7j): White powder; m.p. 226–228 C; IR (KBr)
(νmax/cm-1): 3400, 3300, 3200, 3060, 2970, 2900, 2860, 1640,1610,
5-(3-Bromophenyl)-1,3-diethyl-8-(methylthio)-2-thioxo-2,3,7,10-
tetrahydropyrido[2,3-d:6,5-d’]dipyrimidine-4,6(1H,5H)-dione (7d):
o
White powder; m.p. 223–225 C; IR (KBr) (νmax/cm-1): 3495, 3350,
3200, 3050, 2960, 2900, 2850, 1620, 1610, 1565, 1460, 1380, 1100, 870,
o
1
780, 680; H NMR (400 MHz, DMSO-d6): δ 1.20 (6H, s, 2CH2CH3),
2.56 (3H, s, SCH3), 4.47 (4H, br. s, 2CH2CH3), 5.55 (1H, s, CH),
7.10–7.38 (4H, m, ArH), 7.59 (1H, br. s, NH), 16.75 (1H, br. s, NH–CO)
ppm; 13C NMR (100 MHz, DMSO-d6):δ 12.6, 12.7, 13.3, 34.5, 43.7,
95.3, 95.9, 122.1, 126.2, 129.2, 129.6, 130.7, 142.1, 160.7, 163.1, 164.0,
164.3, 174.8 ppm. Anal. calcd for C20H20BrN5O2S2 (506.44): C, 47.43;
H, 3.98; N, 13.83; found: C, 47.31; H, 3.79; N, 13.68%.
5-(2,4-Dichlorophenyl)-1,3-diethyl-8-(methylthio)-2-thioxo-
2,3,7,10-tetrahydropyrido[2,3-d:6,5-d’]dipyrimidine-4,6(1H,5H)-
dione (7e): White powder; m.p. 228–30 oC; IR (KBr) (νmax/cm-1): 3400,
3300, 3200, 3050, 2960, 2900, 2860, 1635, 1610, 1580, 1520, 1460, 1380,
1100, 1080, 860, 780, 760; 1H NMR (400 MHz, DMSO-d6): δ 1.18 (6H,
t, J=6.8 Hz, 2CH2CH3), 2.54 (3H, s, SCH3), 4.47 (4H, q, J=6.8 Hz,
CH2CH3), 5.50 (1H, s, CH), 7.34 (2H, m, ArH), 7.50 (1H, s, ArH) ppm;
13C NMR (100 MHz, DMSO-d6): δ 12.6, 12.9, 13.3, 34.0, 43.3, 43.7, 95.0,
95.6, 127.1, 129.7, 131.5, 131.7, 132.1, 134.0, 136.6, 160.5, 161.3, 163.2,
163.8, 174.8 ppm. Anal. calcd for C20H19Cl2N5O2S2 (496.43): C, 48.39; H,
3.86; N, 14.11; found: C, 48.55; H, 3.70; N, 14.39%.
1
1580, 1520, 1460, 1380, 1100, 1080, 850, 780, 750; H NMR (400
MHz, DMSO-d6): δ 1.18 (6H, t, J=6.8 Hz, 2CH2CH3), 1.31 (3H, t,
J=7.2 Hz, SCH2CH3), 3.14 (2H, m, SCH2CH3), 4.45 (4H, q, J=6.8 Hz,
2CH2CH3), 5.52 (1H, s, CH), 7.34 (2H, m, ArH), 7.37 (1H, br. s, NH),
7.45 (1H, s, ArH) ppm; 13C NMR (100 MHz, DMSO-d6): δ 12.3, 12.6,
15.1, 24.8, 34.0, 43.3, 43.6, 95.4, 95.9, 127.1, 129.7, 131.5, 131.7, 132.0,
134.0, 159.9, 161.3, 163.5, 164.0, 164.1, 174.7 ppm. Anal. calcd for
C21H21Cl2N5O2S2 (510.46): C, 49.41; H, 4.15; N, 13.72; found: C, 49.18;
H, 4.09; N, 13.55%.
1,3-Diethyl-8-(ethylthio)-5-(naphthalen-1-yl)-2-thioxo-2,3,7,10-
tetrahydropyrido[2,3-d:6,5-d’]dipyrimidine-4,6(1H,5H)-dione
(7k): White powder; m.p. 232–234 oC; IR (KBr) (νmax/cm-1): 3495,
3300, 3200, 3059, 2960, 2910, 2854, 1615, 1580, 1440, 1380, 860, 790,
775, 740; 1H NMR (400 MHz, DMSO-d6): δ 1.10 (6H, m, 2CH2CH3),
1.33 (3H, t, J=7.2 Hz, SCH2CH3), 3.16 (2H, m, SCH2CH3), 4.45 (4H,
m, 2CH2CH3), 6.08 (1H, s, CH), 7.34–7.46 (4H, m, ArH),7.62 (1H, d,
J=8.4 Hz, ArH), 7.79 (1H, d, J =8.0 Hz, ArH), 7.90 (1H, d, J=7.6 Hz,
ArH) ppm; 13C NMR (100 MHz, DMSO-d6): δ 12.5, 12.8, 15.0, 24.8,
33.4, 43.5, 43.7, 81.6, 97.4, 124.0, 125.4, 125.5, 125.7, 125.9, 127.6,
129.2, 131.5, 134.3, 152.1, 159.7, 161.6, 161.8, 164.7, 174.6 ppm. Anal.
calcd for C25H25N5O2S2 (491.63): C, 61.08; H, 5.13; N, 14.25; found: C,
61.29; H, 5.01; N, 14.14%.
1,3-Diethyl-8-(methylthio)-5-(naphthalene-1-yl)-2-thioxo-2,3,7,10-
tetrahydropyrido[2,3-d:6,5-d’]dipyrimidine-4,6(1H,5H)-dione (7f):
o
White powder; m.p. 233–235 C; IR (KBr) (νmax/cm-1): 3500, 3300,
3200, 3050, 2980, 2900, 2850, 1610, 1580, 1440, 1380, 860, 795, 775,
740; 1H NMR (400 MHz, DMSO-d6): δ 1.17 (6H, m, 2CH2CH3), 2.56
(3H, s, SCH3), 4.51 (4H, m, 2CH2CH3), 6.08 (1H, s, CH), 7.38 (4H,
m, ArH), 7.62 (1H, d, J=8.4 Hz, ArH), 7.79 (1H, d, J=8.0 Hz, ArH),
7.90 (1H, d, J=7.6 Hz, ArH) ppm; 13C NMR (100 MHz, DMSO-d6):δ
12.4, 12.7, 13.3, 33.4, 43.6, 81.4, 97.3, 124.0, 125.5, 125.6, 126.0, 127.6,
129.2, 131.5, 132.0, 134.3, 135.0, 160.3, 161.7, 162.6, 163.0, 164.7, 174.6
ppm. Anal. calcd for C24H23N5O2S2 (477.6): C, 60.36; H, 4.85; N, 14.66;
found: C, 60.21; H, 4.59; N, 14.79%.
Conclusions
In summary, we have demonstrated an eco-friendly, efficient and
versatile approach for the synthesis of novel pyridopyrimidines
3a–j and 7a–k using [γ-Fe2O3@HAp-SO3H] as a supported
magnetic nanocatalyst. Reusability of the catalyst, short reaction
times, easy work-up of the products, excellent yields and mild
reaction conditions are the notable features of this protocol.
1,3-Diethyl-8-(methylthio)-5-(pyridine-3-yl)-2-thioxo-2,3,7,10-
tetrahydropyrido[2,3-d:6,5-d’]dipyrimidine-4,6(1H,5H)-dione
(7g): White powder; m.p. 226–228 oC; IR (KBr) (νmax/cm-1): 3500,
1
3400, 3300, 3060, 2970, 2900, 1620, 1585, 1560, 780, 680; H NMR
(400 MHz, DMSO-d6): δ 1.15 (6H, t, J=6.8 Hz, 2CH2CH3), 2.46 (3H,
s, SCH3), 4.42 (4H, m, 2CH2CH3), 5.86 (1H, s, CH), 7.09 (1H, br. s,
NH), 7.76 (1H, dd, J=7.6, 5.6 Hz, ArH), 7.99 (1H, d, J=8.0 Hz, ArH),
8.40 (s, 1H, ArH), 8.59 (1H, d, J=5.2 Hz, ArH) ppm. Anal. calcd for
C19H20N6O2S2 (428.53): C, 53.25; H, 4.70; N, 19.61; found: C, 53.11; H,
4.91; N, 19.45%.
Electronic Supplementary Information
The ESI (NMR spectra of 3a) is available through stl.publisher.
ingentaconnect.com/content/stl/jcr/supp-data
The authors are grateful to the Research Council of the
University of Guilan and the Islamic Azad University, Rasht
Branch, for financial support of this work.
1,3-Diethyl-8-(methylthio)-5-(3-methoxyphenyl)-2-thioxo-2,3,7,10-
tetrahydropyrido[2,3-d:6,5-d’]dipyrimidine-4,6(1H,5H)-dione (7h):