4
04
W. M. Best, C. G. Sims and M. Winslade
+
This material was of sufficient purity for use in Suzuki couplings and
was not characterized further.
M ); 164 (19); 157 (52); 129 (92); 104 (27); 101 (34); 76 (40); 75 (29);
74 (24); 50 (29).
A portion of this boronic acid (1.1 g, 5.4 mmol) and DCNQ (2)
(
(
575 mg, 2.5 mmol) in benzene (25 mL), was treated with Pd(PPh3)4
100 mg) and 2 M aqueous sodium carbonate solution (5.5 mL). The
2-Chloro-7-methoxy-1,4-naphthoquinone (16)
mixture was refluxed overnight before being poured into water and
worked up using dichloromethane extraction in the usual manner. The
crude product was chromatographed (elution with benzene) to give 2,3-
bis(6-methoxy-2-naphthyl)-1,4-naphthoquinone (8) as a red solid (0.92
g, 78%). A small sample was recrystallized from ethyl acetate for
analysis, m.p. 229–230°C (Found: C, 82.0; H, 4.7. C H O requires C,
Following General Procedure B, (16) was prepared in 95% yield from
[
19]
2-hydroxy-7-methoxy-1,4-naphthoquinone (19).
Obtained as a
bright yellow solid, m.p. 170–172°C (Found: C, 59.4; H, 3.1.
1
C H ClO requires C, 59.4; H, 3.2%). H NMR (200 MHz) δ 3.97, s,
1
1
7
3
OMe; 7.17, s, H3; 7.24, dd, J 8.7, 2.6 Hz, H6; 7.60, d, J 2.6 Hz, H8;
8.04, d, J 8.7 Hz, H5. Mass spectrum m/z 224 (33%, M ); 222 (100,
M ); 194 (24); 187 (82); 179 (14); 159 (16); 116 (16); 106 (13); 63 (28);
+
32
22
4
1
+
8
1.7; H, 4.7%). H NMR (300 MHz) δ 3.86, s, OMe; 6.99, d, J 2.5 Hz,
H5´; 7.06, dd, J 8.9, 2.5 Hz, H7´; 7.10, dd, J 8.5, 1.7 Hz, H3´; 7.48, d, J
.5 Hz, H4´; 7.59, d, J 8.9 Hz, H8´; 7.64, br. d, J 1.4 Hz, H1´; 7.78–7.84,
m, H6, H7; 8.20–8.26, m, H5, H8.
62 (15).
8
Acknowledgments
2
-Chloro-3-(1-naphthyl)-1,4-naphthoquinone (9)
We thank the Chemistry Department of the University of
Western Australia, and in particular Dr Lindsay Byrne, for
generous access to their NMR instruments. We also thank
Ms Hiromi Eaton for her assistance with some of this work.
This article is published with the permission of the Director,
Chemistry Centre (WA).
Following General Procedure A, but refluxing for 15 h, (9) was
prepared in 75% yield (after chromatography; elution with 1:1
benzene/hexane) from DCNQ (2) and 1.0 equiv. of 1-naphthylboronic
acid. Obtained as a bright yellow solid, m.p. 201–202°C (Found: C,
7
1
5.3; H, 3.3. C H ClO requires C, 75.4; H, 3.5%). H NMR (300
2
0
11
2
MHz) δ 7.37, dd, J 7.1, 1.1 Hz, H2´; 7.42–7.55, m, 3H; 7.60, dd, J 8.3,
.1 Hz, H3´; 7.80–7.86, m, H6, H7; 7.93–8.00, m, 2H; 8.14–8.19, m,
7
+
H5 or H8; 8.27–8.31, m, H5 or H8. Mass spectrum m/z 320 (47%, M );
References
+
3
18 (100, M ); 284 (20); 283 (78); 255 (45); 227 (30); 226 (92); 151
[
1] J. A. Armstrong, R. W. Baker, W. M. Best, L. T. Byrne, J. R.
Cannon, S. M. Colegate, A. R. Gray, N. G. Marchant, N. Rothnie,
M. V. Sargent, C. G. Sims, Z. E. Spadek, R. D. Trengove, Aust. J.
Chem. 1999, 52, 57.
(24); 150 (22); 127 (18); 113 (55); 76 (18).
3-(2,6-Dimethoxyphenyl)-2-(1-naphthyl)-1,4-naphthoquinone (10)
Following General Procedure A, but refluxing for 40 h, (10) was
prepared in 57% yield (after chromatography; elution with 1:6 ethyl
acetate/hexane) from 2-chloro-3-(1-naphthyl)-1,4-naphthoquinone (9)
and 2.5 equiv. of 2,6-dimethoxyphenylboronic acid. Obtained as a
yellow solid, m.p.166–168°C (Found: C, 80.0; H, 4.8. C H O
[2] I. Takahashi, N. Takeyama, H. Mori, M. Yamamoto, H.
Nishimura, H. Kitajima, Chemistry Express 1992, 7, 709 (see
also reference 17).
[3] S. Yoshida, H. Kubo, T. Saika, S. Katsumura, Chem. Lett. 1996,
2
8
20
4
139.
1
requires C, 80.0; H, 4.8%). H NMR (200 MHz) δ 3.11, s, OMe; 3.76,
s, OMe; 6.14, d, J 8.4 Hz, H3´; 6.43, d, J 8.4 Hz, H5´; 7.04, t, J 8.4 Hz,
[4] S. Katsumura, S. Yoshida, H. Kubo, T. Saika, Jap. Pat. 09077743.
[5] K. W. Stagliano, H. C. Malinakova, Tetrahedron Lett. 1997, 38,
H4´; 7.15–7.46, m, 4H, naphthyl; 7.67–7.88, m, 5H, naphthyl;
6617.
+
8
1
.16–8.30, m, H5, H8. Mass spectrum m/z 421 (30%); 420 (100, M );
04 (15); 76 (15).
[6] K. W. Stagliano, H. C. Malinakova, J. Org. Chem. 1999, 64,
8034.
[
[
[
7] A. R. Martin, Y. Yang, Acta Chem. Scand. 1993, 47, 221. A.
Suzuki. J. Organomet. Chem. 1999, 576, 147.
8] S. Mohri, M. Stefinovic, V. Snieckus, J. Org. Chem. 1997, 62,
3
-Methyl-2-phenyl-1,4-naphthoquinone (11)
Following General Procedure A, but refluxing for 3 h, (11) was
prepared in 86% yield (after chromatography; elution with hexane)
from 2-chloro-3-methyl-1,4-naphthoquinone (15) and 1.2 equiv. of
phenylboronic acid. Obtained as bright yellow plates from ethanol, m.p.
7
072.
9] Y. Fukuyama, Y. Kiriyama, M. Kodama, Tetrahedron Lett. 1993,
4, 7637.
10] N. Tamayo, A. M. Echavarren, M. C. Paredes, J. Org. Chem.
991, 56, 6488.
11] D. W. Old, J. P. Wolfe, S. L. Buchwald, J. Am. Chem. Soc. 1998,
3
[
[
6
8°C (lit. see footnote to Table 1, entry i) (Found: C, 82.3; H, 4.9.
1
1
C H O requires C, 82.2; H, 4.9%). H NMR (200 MHz) δ 2.08, s,
Me; 7.19–7.26, m, 2H, Ph; 7.40–7.52, m, 3H, Ph; 7.69–7.78, m, H6,
H7; 8.06–8.19, m, H5, H8. Mass spectrum m/z 249 (18%); 248 (100,
1
7
12
2
1
1
20, 9722. A. F. Littke, G. C. Fu, Angew. Chem., Int. Ed. Engl.
998, 37, 3387.
+
M ); 247 (32); 233 (30); 231 (40); 219 (46); 191 (19); 189 (17); 165
[
[
[
12] Y. Hoshino, N. Miyaura, A. Suzuki, Bull. Chem. Soc. Jpn 1988,
1, 3008.
13] T. Ishiyama, M. Murata, N. Miyaura, J. Org. Chem. 1995, 60,
508.
14] J. M. Lyons, R. H. Thomson, J. Chem. Soc. 1953, 2910; R. B.
Gupta, R. W. Franck, Synlett 1990, 355.
(10); 115 (18); 104 (39); 76 (48).
6
Preparation of 2-Chloro-1,4-naphthoquinones. General Procedure B
7
2
-Chloro-1,4-naphthoquinone (14)
2
-Hydroxy-1,4-naphthoquinone (17) (350 mg, 2.0 mmol) in benzene
[15] D. E. Kvalnes, J. Am. Chem. Soc. 1934, 56, 2478.
[16] L. R. Buzbee, G. G. Ecke, British Patent 1,128,115 (Chem. Abstr.
1969, 70, 47169x).
(20 mL) was treated with oxalyl chloride (0.50 mL, 5.7 mmol) and
DMF (2 drops). The mixture was stirred at 50°C for 45 min. The
resulting yellow solution was decanted into a clean round-bottom flask
[17] R. D. Clark, C. H. Heathcock, Synthesis 1974, 47.
[18] G. Roberge, P. Brassard, J. Org. Chem. 1981, 46, 4161; Y.
Tamura, M. Sasho, S. Akai, A. Wada, Y. Kita, Tetrahedron 1984,
40, 4539.
[19] A. C. Baillie, R. H. Thomson, J. Chem. Soc. (C) 1966, 2184.
[20] R. F. Silver, H. L Holmes. Can. J. Chem. 1968, 46, 1859.
[21] H. Pluim, H. Wynberg, J. Org. Chem. 1980, 45, 2498.
[22] R. Adams, J. E. Dunbar, J. Am. Chem. Soc. 1956, 78, 4774.
(
to separate it from a small amount of dark oil which adheres to the side)
and evaporated to dryness under reduced pressure. The crude product
388 mg, m.p. 112–114°C) was chromatographed (elution with 1:9
ethyl acetate/hexane) to give 2-chloro-1,4-naphthoquinone (14) (367
(
[
16]
mg, 95%) as bright yellow needles, m.p. 114.5–115°C (lit.
1
8
1
14–115°C). H NMR (200 MHz) δ 7.23, s, H3; 7.75–7.84, m, H6, H7;
+
.08–8.20, m, H5, H8. Mass spectrum m/z 194 (32%, M ); 192 (100,