XANTHENEDIONE SYNTHESIS
515
1715, 1607, 1562, 1471, 1403, 1351, 1294, 1240, 1169, 1140, 1099, 1070, 1026, 1014,
985, 935, 896, 876, 838, 810, 694 cmꢁ1. Anal. calcd. for C23H26Cl2O4: C, 63.16; H,
5.99. Found: C, 63.58; H, 5.47.
Compound 2a. 1H NMR (CDCl3) d: 0.98 (s, 6H, 2 CH3), 1.12 (s, 6H, 2 CH3),
2.20–2.45 (m, 8H, 4 CH2), 4.66 (s, 1H, CH), 7.21–7.40 (m, 5H, ArH); IR (KBr) v.
3030, 2980, 1685, 1670, 1470, 1360, 1200, 1170, 1140, 1005, 740, 700 cmꢁ1. Anal.
calcd. for C23H26O3: C, 78.83; H, 7.47. Found: C, 78.96; H, 7.40.
Compound 2b. 1H NMR (CDCl3) d: 0.99 (s, 6H, 2 CH3), 1.12 (s, 6H, 2 CH3),
2.01–2.21 (m, 8H, 4 CH2), 4.76 (s, 1H, CH), 7.50–7.63 (m, 2H, ArH), 8.06–8.18 (m,
2H, Ar); IR (KBr) v. 3035, 2980, 1660, 1650, 1630, 1520, 1360, 1340, 1200, 1070,
1040, 1000, 870, 830 cmꢁ1. Anal. calcd. for C23H25NO5: C, 69.85; H, 6.37; N,
3.54. Found: C, 69.91; H, 6.60; N, 3.29.
Compound 2c. 1H NMR (CDCl3) d: 1.02 (s, 6H, 2 CH3), 1.13 (s, 6H, 2 CH3),
2.21–2.53 (m, 8H, 4 CH2), 4.85 (s, 1H, CH), 7.43 (s, 1H, ArH), 7.88–7.95 (m, 3H,
ArH); IR (KBr) v. 3030, 2980, 1680, 1675, 1625, 1535, 1365, 1340, 1210, 1175,
1145, 1005, 830, 765, 730, 700 cmꢁ1. Anal. calcd. for C23H25NO5: C, 69.85; H,
6.37; N, 3.54. Found: C, 69.91; H, 6.50; N, 3.39.
Compound 2d. 1H NMR (CDCl3) d: 1.00 (s, 6H, 2 CH3), 1.10 (s, 6H, 2 CH3),
2.06–2.31 (m, 8H, 4 CH2), 4.58 (s, 1H, CH), 5.90 (s, 2H, OCH2O), 6.69–6.78 (m, 3H,
ArH); IR (KBr) v. 2980, 1720, 1630, 1565, 1510, 1490, 1440, 1380, 1360, 1320, 1270,
1230, 1040, 940, 920, 890, 810, 790 cmꢁ1. Anal. calcd. for C24H26O5: C, 73.07; H,
6.64. Found: C, 73.18; H, 6.76.
Compound 2e. 1H NMR (CDCl3) d: 0.98 (s, 6H, 2 CH3), 1.10 (s, 6H, 2 CH3),
2.22–2.50 (m, 8H, 4 CH2), 4.64 (s, 1H, CH), 7.26–7.42 (m, 4H, ArH); IR (KBr) v.
3030, 2980, 1680, 1660, 1620, 1490, 1480, 1360, 1200, 1170, 1140, 1090, 1010,
1000, 850, 840 cmꢁ1. Anal. calcd. for C23H25ClO3: C, 71.77; H, 6.54. Found: C,
71.88; H, 6.44.
Compound 2f. 1H NMR (CDCl3) d: 1.02 (s, 6H, 2 CH3), 1.12 (s, 6H, 2 CH3),
2.30–2.49 (m, 8H, 4 CH2), 4.74 (s, 1H, CH), 7.11–7.25 (m, 4H, ArH); IR (KBr) v.
3030, 1685, 1660, 1620, 1490, 1475, 1365, 1200, 1170, 1136, 1090, 1010, 1000, 850,
840 cmꢁ1. Anal. calcd. for C23H25ClO3: C, 71.77; H, 6.54. Found: C, 71.92; H, 6.41.
Compound 2g. 1H NMR (CDCl3) d: 1.03 (s, 6H, 2 CH3), 1.12 (s, 6H, 2 CH3),
2.21–2.46 (m, 8H, 4 CH2), 4.95 (s, 1H, CH), 7.16 (s, 1H, ArH), 7.39 (d, J ¼ 4 8.4 Hz,
2H, ArH), IR (KBr) v. 3035, 2980, 1685, 1660, 1633, 1490, 1485, 1410, 1360, 1210,
1195, 1155, 1100, 1000, 850, 770 cmꢁ1. Anal. calcd. for C23H24Cl2O3: C, 65.87; H,
5.73. Found: C, 65.94; H, 5.60.
Compound 3g. Pale yellow solid. Mp 273–275ꢀC. IR (KBr): nmax ¼ 3035,
2957, 2872, 2360, 2224, 1633, 1605, 1574, 1513, 1471, 1361, 1300, 1277, 1224,
1
1176, 1144, 1123, 1019, 1002, 853, 568, 527 cmꢁ1; H NMR (300 MHz, CDCl3): d
0.78 (s, 6H), 0.95 (s, 6H), 1.84 (d, J ¼ 17.4 Hz, 2H), 2.08 (d, J ¼ 17.4 Hz, 2H), 2.08
(d, J ¼ 17.4, 2H), 2.15 (d, J ¼ 17.4, 2H), 2.49 (s, 3H), 5.30 (s, 1H), 7.08 (d, J ¼ 7.8 Hz,
2H), 7.15 (d, J ¼ 7.8 Hz, 2H), 7.54 (s, 4H); 13C NMR (75 MHz, CDCl3, all 1C
unless indicated): d 21.4, 26.8 (2C), 29.7 (2C), 32.5 (2C), 33.8, 41.9 (2C), 50.2