My PhD dissertation - Institut Fresnel

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(+)-(M)-2,2’-Dibromo-6,6’-bis(methoxymethoxy)biphenyl (M-34): prepared following the
same protocol, starting from (+)-(M)-6,6’-dibromobiphenyl-2,2’-diol (31); m.p. 67 - 68 °C;
[ ] 20
α D
= +29.4 (c = 1.0, acetone).
(±)-(PM)-2,2’-Dibromo-6,6’-dimethoxybiphenyl (35): Iodomethane (3.4 mL, 7.8 g,
55 mmol) was added to a suspension of 6,6’-dibromobiphenyl-2,2’-diol (31; 8.6 g, 25 mmol)
and finely powdered potassium hydroxide (3.1 g, 55 mmol) in dimethylsulfoxide (25 mL) at
25 °C. After vigorous for 90 min, water (7.0 mL) was added and the precipitate was filtered to
give a white solid. Recrystallization from diethyl ether afforded colorless prisms; m.p. 221 -
223 °C; yield: 8.55 g (90%).
1 H NMR: δ = 7.28 (dd, J = 8.0, 1.2 Hz, 2 H), 7.23 (t, J = 8.0 Hz, 2 H), 6.92 (dd,
J = 8.0, 1.2 Hz, 2 H), 3.74 (s, 6 H) ppm.
13 C NMR: δ = 158.3, 129.9, 128.1, 125.3, 124.6, 110.0, 56.4 ppm.
C14H12Br2O2 (372.05) calcd. C 45.20% H 3.25%
found C 45.55% H 2.96%.
(-)-(P)-2,2’-Dibromo-6,6’-dimethoxybiphenyl (P-35): Prepared following the same
protocol, starting from (-)-(P)-6,6’-dibromobiphenyl-2,2’-diol (31); m.p. 173 - 174 °C;
[ ] 20
α D
= -51.5 (c = 1.0, acetone).
C14H12Br2O2 (372.05) calcd. C 45.20% H 3.25%
found C 45.20% H 3.21%.
(+)-(M)-2,2’-Dibromo-6,6’-dimethoxybiphenyl (M-35): Prepared following the same
protocol, starting from (+)-(M)-6,6’-dibromobiphenyl-2,2’diol (31); m.p. 172 - 174 °C;
[ ] 20
α D
= +51.1 (c = 1.0, acetone).
(±)-(PM)-2,2’-Dibromo-6,6’-diethoxybiphenyl (36): A solution of 6,6’-dibromobiphenyl-2,2’-diol
(31; 8.6 g, 25 mmol) in tetrahydrofuran (25 mL) was added dropwise to a 60% suspension of
sodium hydride in mineral oil (2.0 g, 50 mmol) in tetrahydrofuran (25 mL) at 25 °C. After 30
min, ethyl bromide (5.6 mL, 8.2 g, 75 mmol) was added and the reaction mixture was stirred
for 1 h. Water was then added (50 mL) and phases were decanted. The aqueous layer was