344
I. R. Green, V. I. Hugo, and M. N. Mei
needles. (Masses given refer to the final masses of products obtained after
pooling together.) Mp 144–145 8C (from ethyl alcohol). vmax 3315cm21; dH
2.51 (3H, s, 2-CH3), 3.94 and 4.03 (each 3H, s, OCH3), 6.46 (1H, d, J 2.2,
6-H), 6.67 (1H, s, 3-H), 7.21 (1H, d, J 2.2, 8-H) and 9.18 (1H, s, D2O exchange-
able, 4-OH). dC 24.4 (2-CH3), 55.5 and 56.5 (OCH3), 97.6 (C-6), 99.6 (C-8),
110.3 (C-1)a, 111.5 (C-3), 112.4 (C-2)a, 135.7 (C-4a)b, 138.8 (C-8a)b, 153.9
(C-4)c, 157.5 (C-5)c, and 158.9 (C-7)c. [Found: C, 52.4; H, 4.6%; Mþ
296:298 (1:1). Calc. for C13H13BrO3: C, 52.7; H, 4.4%; M 296 : 298 (1: 1)].
Further elution gave a slight mixture of 29, 30, and 31, which was added to
the mother liquor of the recrystallization. The next product to elute was the
1,3-dibromonaphthol 31 (74 mg, 9.9%) as light brown needles. (Masses given
refer to the final masses of products obtained after pooling together.) Mp
175–177 8C (from ethanol). vmax 3390cm21; dH 2.79 (3H, s, 2-CH3), 3.94
and 4.05 (each 3H, s, OCH3), 6.51 (1H, d, J 2.2, 6-H), 7.24 (1H, d, J 2.2,
8-H) and 10.08 (1H, s, D2O exchangeable, 4-OH). dC 25.7 (2-CH3), 55.6
and 56.8 (OCH3), 98.5 (C-6), 100.3 (C-8), 106.5 (C-1)a, 110.0 (C-2)a, 113.4
(C-3)a, 134.4 (C-4a)b, 137.9 (C-8a)b, 150.5 (C-4)c, 156.5 (C-5)c, and 158.9
(C-7)c. [Found: C, 41.2; H; 3.0%; Mþ 374 : 376 : 378 (1 : 2 : 1). Calc. for
C13H12Br2O3: C, 41.7; H, 3.2%; M 374 : 376 : 378 (1: 2 : 1)].
The mother liquors from the recrystallization were evaporated to a
residue, which was chromatographed on a similar column (1200 ꢀ 25 mm)
to afford 1-bromo-naphthol 29[11] followed by the 3-bromonaphthol 30
(118 mg, 19.9%) as olive needles. (Masses given refer to the final masses of
products obtained after pooling together.) Mp 132–133 8C (from hexane).
vmax 3345 cm21; dH 2.49 (3H, d, J 0.6, 2-CH3), 3.87 and 4.02 (each 3H, s,
OCH3), 6.43 (1H, d, J 2.2, 6-H), 6.61 (1H, d, J 2.2, 8-H), 7.08 (1H, d, J
0.6, 1-H), and 9.82 (1H, s, D2O exchangeable, 4-OH). dC 23.7 (C-2 CH3),
55.4 and 56.4 (OCH3), 97.8 (C-6), 99.0 (C-8), 105.9 (C-2)a, 109.6 (C-3)a,
118.7 (C-1), 135.8 (C-4a)b, 138.1 (C-8a)b, 150.7 (C-4)c, 156.3 (C-5)c, 158.1
(C-7)c. [Found: C, 52.9; H, 4.6%; Mþ 296 : 298 (1 : 1). Calc. for
C13H13BrO3: C, 52.7; H, 4.4%; M 296 : 298 (1 : 1)].
4-Acetoxy-1-bromo-5,7-dimethoxy-2-methylnaphthalene 32
Naphthol 29 (20 mg, 0.07 mmol) was acetylated in acetic anhydride (0.5 mL)
and pyridine (0.2 mL) as described earlier to give the corresponding acetate 32
(22 mg, 93%) as white needles. Mp 150–151 8C (from ethyl alcohol). vmax
1740 cm21; dH 2.34 (3H, s, COCH3), 2.55 (3H, s, 2-CH3), 3.88 and 3.94
(each 3H, s, OCH3), 6.50 (1H, d, J 2.2, 6-H), 6.83 (1H, s, 3-H), and 7.27
(1H, d, J 2.2, 8-H). dC 21.0 (COCH3), 24.3 (C-2 CH3), 55.5 and 56.4
(OCH3), 99.2 (C-6)a, 99.3 (C-8)a, 114.4 (C-2)b, 119.7 (C-3), 120.7 (C-1)b,
136.3 (C-4a)c, 137.5 (C-8a)c, 145.8 (C-4)d, 156.7 (C-5)d, 159.5 (C-7)d, and
170.1 (C55O). [Found: C, 53.3; H, 4.2%; Mþ 338 : 340 (1 : 1). Calc. for
C15H15BrO4: C, 53.1; H, 4.5%; M 338 : 340 (1 : 1)].