Fungitoxicity of Polyhalo-8-quinolinols
1079
1
Yield: 2.7 g (98%); m.p.: 170ꢀC (CH3CN; Ref. [11]: m.p.: 170ꢀC, yield not given); H NMR:
ꢀ 8.80 (d, J24 2:20 Hz, H-2), 8.50 (d, H-4), 8.05 (s, H-6), 11.80 (s, OH) ppm; 13C NMR:
ꢀ 154.61 (C-8), 149.98 (C-2), 137.32 (C-4), 137.07 (C-8a), 129.76 (C-6), 125.88 (C-4a), 120.50
(C-3), 116.91 (C-5), 110.09 (C-7) ppm.
4,5,7-Trichloro-8-quinolinol (6a; C9H4Cl3NO)
6a was prepared from 4-chloro-8-quinolinol [6] (2.0 g, 0.011 mol) in 200 cm3 of acetic acid by stirring
for 6 days at room temperature with NCS (3.2 g, 0.024 mol). The solution was diluted with 1000 cm3
of deionized H2O, and the product was recovered by ®ltration, washing with deionized H2O, and
drying at 50ꢀC.
1
Yield: 3.1 g (98%); m.p.: 154ꢀC (CH3CN); H NMR: ꢀ 8.82 (d, J23 4:68 Hz, H-2), 7.84 (d,
H-3), 7.82 (s, H-6), 11.02 (s, OH) ppm; 13C NMR: ꢀ 149.48 (C-8), 148.92 (C-2), 140.32 (C-4),
140.64 (C-8a), 131.51 (C-6), 125.84 (C-3), 121.72 (C-4a), 116.94 (C-5), 116.11 (C-7) ppm.
4,5,7-Tribromo-8-quinolinol (6b; C9H4Br3NO)
6b was prepared from 4-bromo-8-quinolinol [6] in the same manner as 6a was obtained from
4-chloro-8-quinolinol.
Yield: 1.2 g (70%); m.p.: 150±151ꢀC (CH3CN); 1H NMR: ꢀ 8.67 (d, J23 4:43 Hz, H-2), 8.12
(d, H-3), 8.15 (s, H-6), 11.06 (s, OH) ppm; 13C NMR: 151.46 (C-8), 148.43 (C-2), 140.10 (C-8a),
137.70 (C-6), 130.91 (C-4), 130.29 (C-3), 123.79 (C-4a), 105.59 (C-5), 105.39 (C-7) ppm.
5,6,7-Trichloro-8-quinolinol (4c; C9H4Cl3NO)
4c was prepared from 6-chloro-8-quinolinol [6] as 6a was obtained from 4-chloro-8-quinolinol.
Yield: 99% (0.011 mol run); m.p.: 213±214ꢀC (CH3CN; Ref. [12]: m.p.: 213±214ꢀC, Ref. [13]:
m.p.: 220±225ꢀC, yields not given); NMR data: see Ref. [3].
5,6,7-Tribromo-8-quinolinol (4d; C9H4Br3NO)
4d was prepared from 6-bromo-8-quinolinol [6] as 6a was obtained from 6-chloro-8-quinolinol.
Yield: 97% (0.009 mol run); m.p.: 196ꢀC (CH3CN; Ref. [11]: m.p.: 192ꢀC, yield not given); H
1
NMR: ꢀ 8.98 (dd, J23 4:11 Hz, J24 < 1 Hz, H-2), 8.63 (dd, H-4), 11.48 (s, OH) ppm; 13C NMR:
ꢀ 152.16 (C-8), 149.85 (C-2), 137.67 (C-8a), 136.67 (C-4), 127.14 (C-4a), 127.01 (C-6), 124.57
(C-3), 112.00 (C-5), 108.63 (C-7) ppm.
3,5,6,7-Tetrachloro-8-quinolinol (3a; C9H3Cl4NO)
1a [5] (1.1 g, 0.005 mol) was dissolved in acetic acid (100 cm3) to which NCS was added (1.4 g,
0.0105 mol); the mixture was stirred overnight at 40ꢀC. The solution was diluted with 500 cm3 of
deionized H2O. 3a was removed by ®ltration, washed with deionized H2O, and dried at 50ꢀC.
Yield: 1.39 g (98%); m.p.: 159±160ꢀC (CH3CN); 1H NMR: ꢀ 8.91 (d, J24 2:22 Hz, H-2), 8.39
(d, H-4), 11.68 (s, OH) ppm; 13C NMR: ꢀ 150.83 (C-8), 148.78 (C-2), 135.41 (C-8a), 131.38 (C-6),
131.19 (C-4), 130.87 (C-3), 125.18 (C-4a), 117.19 (C-5), 116.55 (C-7) ppm.
3,5,6,7-Tetrabromo-8-quinolinol (3b; C9H3Br4NO)
3b was prepared from 1b [5] by bromination with NBS in the same manner as 3a was obtained
from 1a.