8
M. R. SK ET AL.
−
1
(
decomp.). R ¼ 0.59 (1:3 EtOAc: pet ether); FTIR (cm ) 3430, 2947, 2365, 1635, 1573,
f
1
1
438, 1403, 1348, 1334, 1286, 1249, 1225, 1074, 1031, 810, 460; H NMR (600 MHz, CDCl )
3
δ (ppm) 14.02 (s, 1H), 8.12 (d, J ¼ 8.4 Hz, 1H), 7.79 (s, 1H), 7.33 (d, J ¼ 8.4, 1H), 4.02 (d,
1
3
J ¼ 10.8, 6H), 2.72 (s, 1H); C NMR (150 MHz, CDCl ) δ (ppm) 189.11, 183.10, 158.67,
3
1
1
5
58.20, 149.80, 143.55 (CH), 133.93, 129.20, 128.09, 125.31, 125.26 (CH), 118.38, 118.25,
17.22 (CH), 61.37 (CH ), 56.38 (CH ), 22.79 (CH ). Anal. Calcd. for C H BrO : C,
3
3
3
17 13
5
4.13; H, 3.47; found: C, 54.43; H, 3.12%.
2
-Bromo-1-hydroxy-8-methoxy-4,6-dimethyl-9,10-anthracenedione (42)
This was prepared (along with its tautomer) from cyanophthalide 38 and acceptor 28 in
8
1% yield following the general procedure described above for the Hauser annulation.
−1
Yellow solid, mp: 228 °C (decomp.). R ¼ 0.67 (1:5 EtOAc: pet ether); FTIR (cm )
f
1
3
432, 2930, 2365, 1600, 1401, 1347, 1319, 1304, 1234, 1215, 1116, 800, 468. For 42: H
NMR (600 MHz, CDCl ) δ (ppm) 14.26 (s, 1H), 7.75 (s, 1H), 7.64–7.63 (m, 1H), 7.05
3
13
(s, 1H), 3.98 (s, 3H), 2.82 (s, 3H), 2.70 (s, 3H); C NMR (150 MHz, CDCl ) δ (ppm)
3
1
1
89.93, 184.26, 163.71, 158.09, 145.29, 142.80 (CH), 138.42, 133.89, 129.11, 124.13 (CH),
23.54, 118.89, 117.87, 109.49 (CH), 55.83 (CH ), 24.06 (CH ), 22.73 (CH ).
3
3
3
t
1
For 42 : H NMR (600 MHz, CDCl ) δ (ppm) 13.4 (s, 1H), 7.64–7.63 (m, 1H), 7.55
3
13
(s, 1H), 7.08 (s, 1H), 3.99 (s, 3H), 2.92 (s, 3H), 2.82 (s, 3H); C NMR (150 MHz, CDCl )
3
δ (ppm) 189.55, 183.94, 164.02, 160.33, 145.51, 138.35, 134.85, 131.38, 128.25 (CH), 124.35
CH), 121.84, 120.31, 116.60, 109.85 (CH), 55.92 (CH ), 23.92 (CH ), 20.18 (CH ). Anal.
(
3
3
3
Calcd. for C H BrO : C, 56.53; H, 3.63; found: C, 56.34; H, 3.41%.
1
7
13
4
Funding
We gratefully acknowledge the Council of Scientific and Industrial Research (CSIR) for financial
support (02(0183)/14/EMRII), and The Department of Science and Technology (DST) for instru-
mental facilities. Md Raja Sk is thankful to IIT Kharagpur and Soumen Chakraborty is thankful
to CSIR for his research fellowship.
References
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