thick orange oil which was used in the next step without further
purification: Rf ~ 0.64 (70% toluene–EtOAc); 1H NMR
(200 MHz, CDCl3) d 3.47 (s, 3 H), 3.77 (s, 2 H), 5.22 (s, 2
H), 6.83 (dd, J ~ 2.2, 8.6 Hz, 1 H), 7.03 (d, J ~ 2.0 Hz, 1 H),
7.69 (d, J ~ 8.6 Hz, 1 H); MS (EI) m/z 210 (Mz, 44), 196 (60),
165 (13), 152 (22), 149 (10), 137 (22), 135 (12), 123 (14), 121
(15), 107 (11), 95 (27), 92 (16), 81 (10), 77 (22), 75 (69), 71 (12),
69 (59), 65 (18), 63 (100).
(R)-6-Hydroxy-5’-nitro-6’-(oct-2-yloxy)[D2,2’-bi-1-
benzothiophene]-3(2H),3’(2’H)-dione (13)
To a solution of 12 (122 mg, 0.23 mmol) in AcOH (20 mL) were
added 3 drops of conc. HCl. The solution was heated at 85 uC
with stirring for 15 min, and then poured into water (200 mL)
and extracted with EtOAc (2 6 75 mL). The combined extracts
were washed with brine (26), dried (MgSO4) and concentrated
to a red solid. Purification by flash chromatography on silica
gel (70% toluene–EtOAc) gave 93 mg (84%) of 13 as a dark red
solid: mp 250–252 uC; Rf ~ 0.52 (70% toluene–EtOAc); 1H
NMR (200 MHz, acetone-d6) d 0.88 (t, J ~ 6.4 Hz, 3 H), 1.20–
1.90 (m, 10 H), 1.45 (d, J ~ 6.2 Hz, 3 H), 2.98 (s, 1 H), 4.94 (m,
1 H), 6.85 (dd, J ~ 2.1, 8.5 Hz, 1 H), 7.09 (d, J ~ 2.2 Hz, 1 H),
7.72 (s, 1 H), 7.74 (d, J ~ 8.4 Hz, 1 H), 8.23 (s, 1H); 13C NMR
(100 MHz, acetone-d6) d 13.7, 19.0, 22.6, 25.1, 29.2, 31.9, 36.1,
77.8, 110.3, 110.8, 115.2, 120.9, 121.4, 123.3, 128.9, 130.9,
134.8, 139.8, 151.3, 155.1, 157.1, 165.6, 186.9, 187.4; MS (CI)
m/z 486 (M z 1, 29), 456 (36), 374 (60), 344 (11), 294 (13), 183
(14), 181 (18), 180 (15), 167 (100), 130 (28), 129 (58), 127 (13),
117 (27), 115 (13), 113 (15), 112 (24), 111 (30), 109 (11); HRMS
(EI) Calcd. for C24H23NO6S2: 485.0967. Found: 485.0944.
6-(Methoxymethyloxy)-2-[4-(N,N-dimethylamino)phenylimino]-
1-benzothiophen-3(2H)-one (9)
A solution of Na2CO3 (666 mg, 6.29 mmol) in water (20 mL)
was combined with 8 (660 mg, 3.14 mmol) and the mixture was
stirred in an oil bath at 70–75 uC. A solution of N,N-dimethyl-
4-nitrosoaniline (546 mg, 3.64 mmol) in water (30 mL) was
then added and the heating continued for 3 h. The mixture was
filtered hot and the residue was washed thoroughly with water
and dissolved in EtOAc–acetone. The organic solution was
dried (MgSO4) and concentrated to give 820 mg (76%) of 9 as a
dark purple solid: mp 139–141 uC; Rf ~ 0.47 (70% toluene–
EtOAc); 1H NMR (300 MHz, acetone-d6) d 3.07 (s, 6 H), 3.49
(s, 3 H), 5.38 (s, 2 H), 6.88 (m, 2 H), 7.04 (dd, J ~ 2.1, 8.4 Hz, 1
H), 7.27 (d, J ~ 2.1 Hz, 1 H), 7.41 (m, 2 H), 7.82 (d,
J ~ 8.7 Hz, 1 H); 13C NMR (100 MHz, acetone-d6) d 40.3,
56.6, 95.1, 112.1, 113.0, 116.0, 123.2, 126.7, 129.4, 136.7, 147.4,
151.7, 164.6, 184.1; MS (EI) m/z 342 (Mz, 9), 178 (11), 177
(22), 146 (34), 145 (100), 130 (11), 129 (31), 119 (15), 107 (22),
103 (22), 102 (23), 95 (16), 78 (72), 75 (53), 69 (24), 63 (99).
HRMS (EI) Calcd. for C18H18N2O3S: 342.1038. Found:
342.1045.
(R)-6-[11-(1,1,1,3,3-Pentamethyldisiloxanyl)undecyloxy]-5’-
nitro-6’-(oct-2-yloxy)[D2,2’-bi-1-benzothiophene]-3(2H),3’(2’H)-
dione (3)
Under an Ar atmosphere, diisopropyl azodicarboxylate (141 mg,
0.69 mmol) was added dropwise to a stirred solution of 13
(79 mg, 0.16 mmol), triphenylphosphine (131 mg, 0.50 mmol),
and 11-(1,1,1,3,3-pentamethyldisiloxanyl)undecanol (78 mg,
0.24 mmol) in dry THF (20 mL). The mixture was stirred at
room temperature for 1 h, and then concentrated to a red solid.
Purification by flash chromatography on silica gel (toluene)
gave 111 mg (88%) of 3 as a red solid, which was further
purified by recrystallization from EtOH after filtration through
(R)-5-Nitro-6-(oct-2-yloxy)-1-benzothiophen-3(2H)-one (11)
A suspension of 10 (470 mg, 1.23 mmol) in a 15% solution of
KOH in 1 : 1 EtOH–H2O (50 mL) was heated to reflux with
stirring for 11 h. After cooling in an ice bath, the solution was
poured into dilute aq. HCl (100 mL) and extracted with
EtOAc. The organic extract was washed with brine, dried
(MgSO4) and concentrated to give 388 mg (97%) of 11 as a
thick purple oil which was used in the next reaction without
further purification: 1H NMR (200 MHz, CDCl3) d 0.85 (t,
J ~ 6.3 Hz, 3 H), 1.10–1.90 (m, 10 H), 1.38 (d, J ~ 6.0 Hz, 3
H), 3.85 (s, 2 H), 4.56 (m, 1 H), 6.95 (s, 1 H), 8.18 (s, 1 H).
a
0.45 mm PTFE filter: Rf ~ 0.63 (toluene); 1H NMR
(300 MHz, CDCl3) d 0.01 (s, 6 H), 0.03 (s, 9 H), 0.48 (t,
J ~ 7.1 Hz, 2 H), 0.86 (t, J ~ 6.8 Hz, 3 H), 1.20–1.90 (m, 28
H), 1.41 (d, J ~ 6.3 Hz, 3 H), 3.99 (t, J ~ 6.5 Hz, 2 H), 4.61
(m, 1 H), 6.71 (dd, J ~ 2.0, 8.6 Hz, 1 H), 6.83 (d, J ~ 1.8 Hz, 1
H), 7.03 (s, 1 H), 7.69 (d, J ~ 8.7 Hz, 1 H), 8.22 (s, 1 H); 13C
NMR (100 MHz, CDCl3) d 0.7, 2.3, 14.4, 18.7, 19.6, 22.9, 23.6,
25.4, 26.2, 29.3, 29.4, 29.66, 29.69, 29.87, 29.89, 29.94, 32.0,
33.7, 36.3, 69.4, 78.1, 109.0, 109.1, 114.6, 121.0, 122.1, 124.4,
128.7, 131.0, 135.3, 139.5, 151.5, 155.3, 157.4, 166.4, 187.0,
187.9; Anal. Calcd. for C40H59NO7S2Si2: C, 61.11; H, 7.56; N,
1.78; S, 8.16. Found: C, 61.37; H, 7.35; N, 1.79; S, 7.99.
(R)-6-(Methoxymethyloxy)-5’-nitro-6’-(oct-2-yloxy)[D2,2’-bi-1-
benzothiophene]-3(2H),3’(2’H)-dione (12)
Under an Ar atmosphere, a solution of 11 (388 mg, 1.20 mmol)
in chlorobenzene (15 mL) was added dropwise over 45 min to a
stirred solution of 9 (180 mg, 0.53 mmol) in chlorobenzene
(10 mL) kept at 85 uC. The mixture was stirred at 85 uC for
80 min, then piperidine (1 mL) was added and the heating was
continued for 1 h. After cooling, the mixture was concentrated
to a dark purple residue which was purified by flash
chromatography on silica gel (90% toluene–EtOAc) to give
122 mg (44% from 9) of 12 as a dark purple solid: mp ~ 155–
157 uC; Rf ~ 0.71 (70% toluene–EtOAc); 1H NMR (200 MHz,
CDCl3) d 0.87 (t, J ~ 6.8 Hz, 3 H), 1.20–1.90 (m, 10 H), 1.42
(d, J ~ 6.2 Hz, 3 H), 3.50 (s, 3 H), 4.65 (m, 1 H), 5.27 (s, 2 H),
6.95 (dd, J ~ 2.2, 8.8 Hz, 1 H), 7.10 (s, 1 H), 7.15 (d,
J ~ 2.2 Hz, 1 H), 7.85 (d, J ~ 8.8 Hz, 1 H), 8.35 (s, 1 H); 13C
NMR (100 MHz, CDCl3) d 14.4, 19.7, 22.9, 25.4, 29.4, 32.0,
36.3, 57.0, 78.1, 94.7, 109.2, 111.1, 115.6, 121.0, 123.2, 124.6,
128.9, 131.4, 135.2, 139.6, 151.4, 155.3, 157.5, 164.4, 187.3,
188.4; MS (CI) m/z 530 (M z 1, 12), 500 (21), 418 (14), 294
(24), 225 (19), 223 (10), 212 (15), 211 (100), 182 (21), 181 (39),
179 (11), 167 (74), 165 (13), 130 (14), 129 (40), 122 (11), 113
(11), 112 (16), 111 (16), 110 (23). HRMS (EI) Calcd. for
C26H27NO7S2: 529.1229. Found: 529.1223.
(R)-6-[11-(1,1,1,3,3,5,5-Heptamethyltrisiloxanyl)undecyloxy]-
5’-nitro-6’-(oct-2-yloxy)[D2,2’-bi-1-benzothiophene]-3(2H),3’(2’H)-
dione (4)
Under an Ar atmosphere, diisopropyl azodicarboxylate (70 mg,
0.35 mmol) was added dropwise to a stirred solution of 13
(65 mg, 0.13 mmol), triphenylphosphine (77 mg, 0.29 mmol),
and 11-(1,1,1,3,3,5,5-heptamethyltrisiloxanyl)undecanol (98 mg,
0.25 mmol) in dry THF (22 mL). The mixture was stirred
at room temperature for 1.25 h, and then concentrated to a red
solid. Purification by flash chromatography on silica gel
(toluene) gave 39 mg (34%) of 4 as a red solid, which was
further purified by recrystallization from EtOH after filtration
1
through a 0.45 mm PTFE filter: Rf ~ 0.63 (toluene); H NMR
(200 MHz, CDCl3) d 0.00 (s, 6 H), 0.04 (s, 6 H), 0.06 (s, 9 H),
0.51 (t, J ~ 7.4 Hz, 2 H), 0.87 (t, J ~ 6.8 Hz, 3 H), 1.10–1.90
(m, 28 H), 1.42 (d, J ~ 6.0 Hz, 3 H), 4.04 (t, J ~ 6.3 Hz, 2 H),
4.64 (m, 1 H), 6.78 (dd, J ~ 1.8, 8.6 Hz, 1 H), 6.91 (d,
J ~ 2.0 Hz, 1 H), 7.08 (s, 1 H), 7.79 (d, J ~ 8.4 Hz, 1 H), 8.31
(s, 1 H); 13C NMR (100 MHz, CDCl3) d 0.5, 1.6, 2.1, 14.4, 18.6,
19.7, 22.9, 23.0, 23.5, 25.4, 26.2, 29.2, 29.4, 29.6, 29.8, 29.9,
32.0, 32.2, 33.8, 36.3, 69.4, 78.1, 109.11, 109.14, 114.7, 121.0,
J. Mater. Chem., 2001, 11, 2459–2464
2463