JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Solvent-free Synthesis of Xanthene Derivatives
9-(4-Methoxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,
9-hexahydro-1H-xanthene-1,8(2H)-dione: White solid;
mp 252–254 ꢀC; IR (KBr, cm−1): 3075, 3004, 2958,
1678, 1665, 1625, 1607, 1511, 1358, 1195, 1138, 1034,
842, 571; 1H NMR (250MHz, DMSO-d6): δ (ppm)
0.86 (s, 6H, CH3), 0.99 (s, 6H, CH3), 2.00 (d, 4H,
CH2, J = 7.5 Hz), 2.19 (s, 4H, CH2, J = 8.7 Hz),
2.41–2.57 (distorted AB system) 3.64 (s, 3H, OCH3)
4.41 (s, 1H), 6.72 (d, 2H, ArH, J = 7.5 Hz), 7.01 (d,
2H, ArH, J = 7.5 Hz); 13C NMR (62.5 MHz, DMSO-
d6): δ (ppm) 26.8, 29.1, 30.7, 32.2, 38.8, 39.2, 39.5,
39.8, 40.2, 40.5, 40.8, 50.4, 55.3, 66.7, 113.6, 115.0,
129.4, 163.1, 196.5.
116.2, 125.6, 125.8, 126.4, 127.2, 128.2, 131.4, 133.3,
143.1, 163.0, 196.6.
General procedure for the synthesis of tetra-hydrobenzo
[a]xanthene-11-one derivatives using PDNES
To a mixture of dimedone (0.140 g 1 mmol),
β-naphthol (0.144 g, 1 mmol), and aldehydes (1 mmol)
in a round-bottom flask, PDNES (5 mol%) was added.
The resulting mixture was first stirred magnetically at
110 ꢀC for an appropriate time (Table 7). After comple-
tion of the reaction, as monitored by TLC, the reaction
mixture was cooled to room temperature, and warm
EtOH (30 mL) was added to it. The catalyst did not
ressolve in EtOH and could be easily separated from
the reaction mixture. Finally, the product was recrystal-
lized in ethanol (90%). PDNES was dried and reused
for the next run. The spectra of products were given in
supporting information.
9-(4-hydroxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-
hexahydro-1H-xanthene-1,8(2H)-dione: White solid; mp
−1
ꢀ
253–255 C; IR (KBr, cm ): 3041, 3026, 2962, 1666,
1651, 1614, 1513, 1449, 1360, 1200, 1166, 1006,
839, 5531; 1H NMR (250MHz, DMSO-d6): δ (ppm) 0.86
(s, 6H, CH3), 0.99 (s, 6H, CH3), 2.00 (d, 4H, CH2,
J = 7.5 Hz), 2.19 (d, 4H, CH2, J = 7.5 Hz), 2.40 (d, 4H,
CH2, J = 8.7 Hz), 2.48 (d, 4H, CH2, J = 10 Hz) 4.37 (s,
1H), 6.53 (d, 2H, ArH, J = 5 Hz), 6.89 (d, 2H, ArH,
J = 7.5 Hz), 9.17 (s, 1H, OH); 13C NMR (62.5 MHz,
DMSO-d6): δ (ppm) 26.8, 29.1, 30.5, 32.2, 50.4, 114.9,
115.2, 129.3, 135.2, 155.8, 163.0, 196.5.
Selected physical and spectral data of the products
12-(2,4-Dicholorophenyl)-9,9-dimethyl-9,10-dihydro-
8H-benzo[a]xanthene-11(12H)one: White solid; mp
−1
ꢀ
182–184 C; IR (KBr, cm ): 3049, 2953, 2868, 1651,
1
1619, 1596, 1418, 1369, 1227, 1176, 1046, 813, 750; H
9-(4-Bromophenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-
hexahydro-1H-xanthene-1,8(2H)-dione: White solid; mp
NMR (250 MHz, DMSO-d6): δ (ppm) 0.86 (s, 3H, CH3),
1.02 (s, 3H, CH3), 2.03 (d, 2H, CH2, J = 7.5 Hz), 2.27
(d, 2H, CH2, J = 6.25 Hz), 2.47 (d, 2H, CH2, J = 10
Hz), 2.62 (d, 2H, CH2, J = 8.7 Hz), 5.74 (s, 1H),
7.22–7.47 (m, 6H, ArH), 7.86-8.01 (m, 3H, ArH); 13C
NMR (62.5 MHz, DMSO-d6): δ d (ppm) 26.5, 29.3,
32.1, 32.7, 50.5, 112.1, 116.2, 117.6, 123.3, 125.5, 127.7,
127.9, 129.1 , 129.3, 130.1, 131.2, 131.4, 132.1, 133.3,
133.5, 141.3, 147.7, 164.7, 196.1.
241–243 C; IR (KBr, cm−1): 2951, 2877, 1678, 1660,
ꢀ
1
1624, 1361, 1198, 1009, 852, 526; H NMR (250 MHz,-
CDCl3): δ (ppm) 0.98 (s, 6H, CH3), 1.01(s, 6H, CH3),
2.12 (d, 4H, CH2, J = 7.5 Hz), 2.21 (d, 4H, CH2,
J = 7.5 Hz), 2.45 (s, 4H, CH2 ), 4.69 (s, 1H), 7.15 (d,
2H, ArH, J = 10 Hz), 7.31 (d, 2H, ArH, J = 12.5 Hz);
13C NMR (62.5 MHz, DMSO-d6): δ (ppm) 26.9, 29.0,
31.4, 32.3, 50.3, 66.7, 114.3, 130.7, 131.1, 144.1,
163.5, 196.5.
9,9-Dimethyl-12-(3-nitrophenyl)-9,10-dihydro-8H-
benzo[a]xanthene11(12H)-one: White solid; mp
170–172 C; IR (KBr, cm−1): 3064, 2958, 1649, 1620,
ꢀ
9-(naphthalen-1-yl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-
hexahydro-1H-xanthene-1,8(2H)-dione: White solid; mp
1530, 1469, 1374, 1349, 1224, 1177, 812, 748,
232–234 C; IR (KBr, cm−1): 3049, 2956, 1668, 1627,
726, 682; H NMR (250 MHz, DMSO-d6): δ (ppm)
1
ꢀ
1614, 1356, 1200, 1196, 1005, 782, 768; 1H NMR
(250 MHz, DMSO-d6): δ (ppm) 0.82 (s, 6H, CH3), 0.99
(s, 6H, CH3), 1.90 (d, 4H, CH2, J = 8.7 Hz ), 2.16
(d, 4H, CH2, J = 8.7 Hz), 2.47-2.63 (t, 4H, CH2,
J = 12.5 Hz), 5.29 (s, 1H), 7.12 (d, 1H, J = 7.5 Hz),
7.32–7.55 (m, 7H, ArH), 7.63 (d, 1H, J = 7.5 Hz), 7.78
(d, 1H, J = 7.5 Hz), 8.66 (d, 1H,); 13C NMR
(62.5 MHz, DMSO-d6): δ (ppm) 26.7, 29.1, 32.2, 50.4,
0.81 (s, 3H, CH3), 1.01 (s, 3H, CH3), 2.07 (s, 2H,
CH2, J = 6.2 Hz), 2.20 (d, 2H, CH2, J = 11.2 Hz),
2.53 (d, 2H, CH2, J = 8.7 Hz), 2.63 (d, 2H, CH2,
J = 8.7 Hz), 5.74 (s, 1H), 7.39 –8.03 (m, 9H, ArH),
8.14 ( s, 1H, ArH); 13C NMR (62.5 MHz, DMSO-d6):
δ (ppm) 26.5, 29.1, 32.3, 34.4, 50.4, 112.7, 116.3,
117.6, 121.9, 122.9, 123.6, 125.6, 127.9, 129.0, 130.2,
130.8, 131.5, 135.2, 147.3, 147.6, 148.0, 164.8, 196.4.
J. Chin. Chem. Soc. 2017
© 2017 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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