760
J. B. Christensen and K. Bechgaard
Vol. 40
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This compound was prepared from 2,6-dimethyl-1,5-dihy-
droxynaphthalene [1] and 1-bromo-3,3-dimethyl-2-butanone
[16] according to the procedure for 2a. An analytical sample
crystallized from EtOH had mp. 113 – 113 ºC (solidified and
melted again: 130 –132 ºC);1H nmr (deuteriochloroform): d 1.22
(s, 18 H), 2.41 (s, 6 H), 4.80 (s, 4 H), 7.33 (d, 2 H, J = 8.50 Hz),
7.78 (d, 2 H, J = 8.50 Hz).
% yield (based on 3b) as yellow crystals with mp. >260 ºC; H
nmr (carbondisulfide): d 1.60 (s, 6 H), 2.75 (s, 12 H), 5.80 (s, 2
H), 5.82 (s, 2 H), 6.39 (d, J = 8.8 Hz, 4 H), 6.82 (d, J = 8.8 Hz, 4
H); MS (EI): 474 (M+), 458, 415, 237, 201, 157.
Anal. Calcd. For C32H30N2O2: C, 80.98; H, 6.37; N, 5.90.
Found: C, 81.35; H, 6.44; N, 5.63.
2,7-Dimethyl-3,8-bis(2-fluorphenyl)-1,6-dioxapyrene (1i).
Was prepared from 2i by the general procedure in 12 % yield
Anal. Calcd. For C24H32O4: C, 74.97; H, 8.39. Found: C,
74.93; H, 8.43.
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as an orange powder; Mp. 281 - 284 ºC (dec.); H nmr (car-
2,6-Dimethyl-1,5-bis(1-(2-fluorphenyl)-1-oxo-2-ethoxy)naph-
thalene (2i).
bondisulfide): d 1.62 (s, 6 H); 5.54 (s, 2 H); 5.93 (s, 2 H), 7.0 (m,
8 H); MS(EI): 424 (M+), 395, 351, 212, 151.
Anal. Calcd. For C28H18F2O2: C, 79.23; H, 4.27. Found: C,
79.48; H, 4.44.
2,6-Dimethyl-1,5-dihydroxynaphthalene [1] was alkylated
with 1-(2-fluorphenyl)-2-bromo-1-ethanone [22] according to the
general procedure. The work-up was carried out by pouring the
reaction mixture into water, whereby the crude product precipi-
tated; yield: » 100%. An analytical sample crystallized from
toluene (treatment with activated carbon) had mp. 193 –195 ºC;
1H nmr (deuteriochloroform): d 2.50 (s, 6 H), 5.20 (s, 4 H), 7.20
– 8.10 (m, 12 H).
2,7-Dimethyl-3,8-bis(4-fluorphenyl)-1,6-dioxapyrene (1j).
This compound was prepared from 2j by the general procedure
in 29 % yield as a yellow powder; Mp. 288 - 290ºC; 1H nmr (car-
bondisulfide): d 4.69 (s, 6 H), 8.86 (s, 2 H), 9.03 (s, 2 H), 9.91 (m,
4 H), 10.10 (m, 4 H); 13C nmr (CPMAS): d 20.2, 118.5, 122.3,
124.9, 128.5, 131.9, 136.5, 139.5, 145.6, 151.4; MS (EI): 424
(M+), 395, 381, 336, 257, 212, 165.
Anal. Calcd. For C28H18F2O4: C, 73.03; H, 4.82. Found: C,
73.21; H, 4.92.
Anal. Calcd. For C28H18F2O2: C, 79.23; H, 4.27. Found: C,
79.35; H, 4.36.
2,6-Dimethyl-1,5-bis(1-(4-fluorphenyl)-1-oxo-2-ethoxy)naph-
thalene (2j).
2,7-Dimethyl-3,8-bis(4-chlorphenyl)-1,6-dioxapyrene (1k).
2,6-Dimethyl-1,5-dihydroxynaphthalene [1] was alkylated
with 1-(4-fluorphenyl)-2-bromo-1-ethanone [22] according to the
general procedure. The work-up was carried out by pouring the
reaction mixture into water, whereby the crude product precipi-
tated; yield: » 100%. An analytical sample crystallized from
toluene (treatment with activated carbon) had mp. 174 –176 ºC;
1H nmr (deuteriochloroform): d 2.40 (s, 6 H), 5.20 (s, 4 H), 7.20
(m, 6 H), 7.90 (m, 6 H).
This compound was prepared from2k according to the general
procedure. The crude product precipitated during the treatment
with NaOH/Na2S2O4 and was isolated by filtration. After drying,
the product was purified by Soxlet extraction with CH2Cl2 to
give 1k in 26 % yield as a yellow powder; Mp. > 300ºC. An ana-
lytical sample was prepared by sublimation in vacuo (300
ºC/0.01 mm Hg); 13C nmr (CPMAS): d 25.0, 123.3, 127.0, 129.6,
133.3, 136.6, 141.3, 144.0, 150.2, 156.1; MS(EI): 456 (M+), 427,
393, 313, 228, 157.
Anal. Calcd. For C28H18F2O4: C, 73.03; H, 4.82. Found: C,
73.38; H, 4.91.
Anal. Calcd. For C28H18Cl2O2: C, 73.53; H, 3.97; Cl, 15.50.
Found: C, 73.43; H, 4.09; Cl, 15.74.
2,6-Dimethyl-1,5-bis(1-(4-chlorphenyl)-1-oxo-2-ethoxy)naph-
thalene (2k).
2,6-Dibromo-1,5-bis(2-oxo-3-butoxy)naphthalene (2a).
2,6-Dimethyl-1,5-dihydroxynaphthalene [1] was alkylated with
1-(4-chlorphenyl)-2-bromo-1-ethanone [22] according to the gen-
eral procedure. The work-up was carried out by pouring the reac-
tion mixture into water, whereby the crude product precipitated;
yield: » 100%. An analytical sample crystallized from toluene
General Procedure for Alkylations.
To a degassed mixture of 10 g K2CO3 (72 mmol) in 100 mL
DMF was added 10.0 g 2,6-dibromo-1,5-dihydroxynaphthalene
[12] (31 mmol) followed by 7 mL 3-bromo-2-butanone [15].
Stirring at RT overnight. The DMF was removed in vacuum, and
the dark residue was dissolved in an ether/H2O-mixture. The
organic phase was separated, dried over MgSO4 and concentrated
in vacuo. The crude product was then purified by column chro-
matography on Silicagel 60 (0.040 – 0.063 mm) with ether:petro-
leum ether (1:1) as eluent to give 9.7 g (67%) of 2a as a yellow-
ish-white powder. An analytical sample crystallized from
1
(treatment with activated carbon) had mp. 199 –201 ºC; H nmr
(deuteriochloroform): d 2.40 (s, 6 H), 5.20 (s, 4 H), 7.50 (m, 12 H).
Anal. Calcd. For C28H18Cl2O4: C, 68.16; H, 4.49; Cl, 14.37.
Found: C, 68.30; H, 4.35; Cl, 14.07.
2,6-Di-t-butyl-1,5-dihydroxynaphthalene (3c).
A mixture of 80.0 g 1,5-dihydroxynaphthalene (0.50 mol),
75.0 g t-butanol (1.01 mol), 300 g acetic acid and 750 g 85%
phosphoric acid was stirred (mechanical stirring) under N2 at 85
ºC overnight. The mixture was cooled to RT and filtered. The
crude product was washed with water, dried in vacuo and crystal-
lized from toluene (treatment with activated carbon) to give 32.6
g (24 %) of pure (3c) mp. 155 – 157 ºC. A second crop of mater-
ial (8.7 g (6 %)) could be isolated by concentration of the mother
liquor; 1H nmr (deuteriodimethylsulfoxide): d 1.67 (s, 18 H),
5.02 (s, 2 H), 7.58 (d, 2 H, J = 8.9 Hz), 7.78 (d, 2 H, J = 8.9 Hz);
13C nmr (deuteriodimethylsulfoxide): d 28.7, 33.6, 111.8, 123.2,
126.0, 129.9, 149.4.
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ether/petroleum ether had mp. 115 – 117 ºC; H nmr (deuteri-
ochloroform): d 1.40 (d, 3 H, J = 6.7 Hz), 2.49 (s, 3 H), 4.91 (q, 1
H, J = 6.7 Hz), 7.60 (d, 2 H, J = 8.8 Hz), 7.9 (d, 2 H, J = 8.8 Hz);
13C nmr (deuteriochloroform): d 17.2, 26.3, 84.3, 113.5, 120.2,
130.8, 131.4, 150.6, 207.8.
Anal. Calcd. For C18H18Br2O4: C, 47.19; H, 3.96; Br, 34.88.
Found: C, 47.29; H, 4.00; Br, 34.55.
2,6-Dimethyl-1,5-bis(3,3-dimethyl-2-oxo-1-butoxy)naphthalene
(2e).