210
A. A. O. Sarhan et al.
2,3-Diethoxy-1,4-naphthoquinone (8; C14H14O4)
A mixture of 0.55 g (2.5 mmol) 1, 0.31 g 3,4-dimethylphenol (2.5 mmol), and 0.5 g t-BuOK was
stirred in ethanol for 6h. The reaction mixture was worked up as mentioned above and
ꢀ
chromatographed (silica gel, ether/cyclohexane 1:6) to give 8 in 37% yield, m.p.: 80 C.
1
H NMR (CDCl3): ꢀ 1.45 (t, J 7 Hz, 6H, 2CH3), 4.4 (q, J 7 Hz, 4H, 2 OCH2), 7.7 (m, 2H,
1
3
Ar-H), 8.05 (m, 2H, Ar-H)ppm; C NMR (CDCl3): ꢀ 15.599 (� , 2 CH3), 69.651 (, 2 OCH2-2,3),
1
26.061 (� , Ar-CH), 130.720 (, C-4a, C-8a), 133.982 (� , Ar-CH), 147.397 (, C-2, C-3), 182.100
(
(
, 2 C=O, C-1, C-4)ppm; MS: m/z (%) 246 [M ] (35), 231 (4), 218 (34), 217 (77), 211 (9), 203
18), 191 (13), 174 (17), 162 (100), 146 (30), 133 (18), 122 (25), 107 (34), 105 (47), 91 (7), 89 (15),
88 (23), 77 (33), 76 (31), 65 (4).
2
-Ethoxy-1,4-naphthoquinone (9; C12H10O3) and 1-hydroxybenzo[b]-naphtho-
2,3-e]dioxine-6,11-quinone (10; C16H8O5)
[
A mixture of 1.14 g (5 mmol) 1, 1.0 g pyrrogallol (7.9 mmol), and 1.0 g t-BuOK was re¯uxed in
0 ml ethanol for 6 h. The reaction mixture was concentrated to dryness and washed several times
2
with water to remove the excess of pyrrogallol and of course t-BuOK. The residue was dissolved in
CHCl3, dried (MgSO4), and ®ltered. The combined ®ltrate was concentrated and chromatographed
on silica gel (ether/cyclohexane 1:1) to give yellow crystals of 7 (43%) in the ®rst fraction followed
by 9 (9.5%) in the second fraction. The ®nal fractions separated from the ¯ash column gave 5% of
the corresponding 1-hydroxybenzo[b]naphtho[2,3-e]dioxine-6,11-quinone (10).
ꢀ
1
9
: M.p.: 91 C; H NMR (CDCl3): ꢀ 1.55 (t, J 7Hz, 3H, CH3), 4.1 (q, J 7 Hz, 2H, OCH2),
6
.15 (s, 1H-3), 7.65±7.8 (m, 2H, Ar-H), 8.05±8.15 (m, 1H, Ar-H), 8.2 (m, 1H, Ar-H)ppm; MS: m/z
(
(
%) 202 [M ] (100), 187 (15), 180 (2), 173 (20), 167 (2), 160 (31), 158 (79), 146 (31), 135 (3), 130
32), 118 (7), 105 (83), 102 (40), 89 (44), 77 (30), 76 (27), 69 (16), 65 (2).
ꢀ
1
1
0: M.p.: 268±270 C; H NMR (DMSO-d6): ꢀ 6.5 (dd, J 1 Hz, J 9 Hz, 1H, Ar-H), 6.62 (dd,
J 1 Hz, J 9 Hz, 1H, Ar-H), 6.83 (dd like t, J 0.0 Hz, J 9 Hz, 1H, Ar-H), 7.85 (m, 2H, Ar-H),
1
3
8
1
1
.0 (m, 2H, Ar-H), 10.22 (s, 1H, OH)ppm; C NMR (DMSO-d6) ꢀ 107.384, 114.404, 125.208,
25.857 (� , Ar-CH), 129.037, 129.912, 129.954 (, Ar-C), 134.452 (� , Ar-CH), 138.948, 139.392,
41.394, 146.476 (, Ar-C), 177.182, 177.212, (, C=O, C-1, C-4)ppm; MS: m/z (%) 280 [M ]
(
(
100), 251 (8), 223 (6), 210 (2), 196 (9), 180 (2), 173 (30), 168 (11), 152 (3), 149 (3), 139 (12), 128
4), 120 (3), 112 (5), 108 (38), 104 (10), 97 (3), 89 (10), 77 (8), 76 (19), 65 (2).
0 0
-(3 -Hydroxy-4 -aldehydophenoxy)-3-chloro-1,4-naphthoquinone (11a; C17H9ClO5)
2
0
0
and 2-(3 -Hydroxy-5 -aldehydophenoxy)-3-chloro-1,4-naphthoquinone (11b; C17H9ClO5)
A mixture of 1.14 g (5 mmol) 1 , 0.4 g 2,4-dihydroxybenzaldehyde (5 mmol), and 0.5 g K2CO3 was
stirred in 20 ml acetone for 3 h. The reaction mixture was concentrated to dryness and washed several
times with water. The residue was dissolved in CHCl3, dried (MgSO4), and ®ltered. The combined
®
ltrate was concentrated and chromatographed on silica gel (ether/cyclohexane 1:2) to give yellow
crystals of a mixture of 11a and 11b in 81% overall yield. From this mixture, only 11b could be
1
puri®ed suf®ciently by further chromatography. 11a: H NMR (CDCl3): ꢀ 6.5±8.2 (m, 7H, Ar-H),
1
9
.7 (s, 1H, CHO), 11.38 (s, 1H, OH)ppm; MS: m/z (%) 329 [M ] (2), 328 [M ] (2), 293 (2), 265
(
2), 241 (1), 234 (3), 225 (1), 209 (2), 195 (1), 184 (3), 171 (1), 167 (2), 156 (2), 149 (3), 138 (82),
1
37 (100), 129 (2), 120 (4), 109 (12), 97 (4), 92 (9), 81 (30), 77 (4), 65 (5).
ꢀ
1
1
1b: M.p.: 168±169 C; H NMR (DMSO-d6): ꢀ 6.8±6.9 (m, 2H, Ar-H), 7.67±8.15 (m, 5H, Ar-
13
H), 10.1 (s, 1H, CHO), 11.1 (s, 1H, OH)ppm; C NMR (DMSO-d6): ꢀ 104.222, 108.432, 126.756,
1
1
26.919, 132.392, 134.740. 131.917, (� , Ar-CH), 118.701, 130.707, 131.670, 134.584, 151.737,
62.094, 162.781, (, Ar-C), 177.684, 178.159, (, 2C=O, C-1, C-4,), 191.230 (� , CHO)ppm; MS:
m/z (%) 329 [M ] (9), 328 [M ] (28) 327 [M ] (100), 310 (2), 301 (7), 299 (17), 293 (58), 282
1
� 1