Journal of The Electrochemical Society, 163 (10) H896-H905 (2016)
H899
tetrahydro-2H-[1,4]dioxocino[2,3-c]pyrrole-7,9-dicarboxylic acid
6) (0.50 g, 1.7 mmol) was dissolved in 5 ml triethanolamine. The
down to room temperature and was poured into ice-water. After then,
the mixture was extracted with DCM, washed with brine and water,
respectively. DCM was removed under reduced pressure and the final
(
homogeneous brown solution was stirred under a nitrogen flow
◦
in a preheated oil bath at 130 C. The reaction was complete in
product was purified by column chromatography (SiO
2
, DCM) to give
approximately 30 min as monitored by TLC. The flask content
allowed to cool down to room temperature, and mixed with ice-water
and then, extracted with DCM, washed with brine and water. Solvent
was removed under reduced pressure after drying the organic layer
over anhydrous sodium sulfate. The crude product was purified by
2-butyl-5,10-dihydro-2H-benzo[6,7][1,4]dioxocino[2,3-c]pyrrole
13
(10) as light gray oily solid (0.16 g) in 43% yield. C-NMR (400
MHz, CDCl ) δC/ppm: 13.8, 20.0, 33.4, 50.2, 75.2, 106.1, 128.6,
3
130.3, 135.8, 136.9.
1
H-NMR (400 MHz, CDCl
3
) δH/ppm: 0.87 (t, J = 7.6 Hz, 3H,
), 1.60 (p, J =
), 5.29 (s,
column chromatography (SiO
2
, hexane/ethyl acetate, 2:1, v/v) to
butyl -CH
7.6 Hz, 2H, butyl -CH
3
), 1.23 (sextet, J = 7.9 Hz, 2H, butyl -CH
2
give 8-Butyl-3,4,5,8-tetrahydro-2H-[1,4]dioxocino[2,3-c]pyrrole (7)
2
), 3.57 (t, J = 7.2 Hz, 2H, N-CH
2
1
as light yellow oily solid (0.15 g) in 41% yield. H-NMR (400 MHz,
4H), 6.10 (s, 2H, pyrrole), 7.25 (m, 4H). MS (EI) m/z (%) calcd. for
+
CDCl
Hz), 1.64 (p, 2H, J = 7.6 Hz), 1.89 (t, 4H, J = 7.2 Hz), 3.64 (t, 4H, J
7.2 Hz), 3.94 (t, 2H, J = 6.8 Hz), 6.10 (s, 2H). MS (EI) m/z (%)
calcd. for C18
: 209.2; found: 209.2 (M+, 100), 187 (12), 152
5), 137 (15.5), 125 (28), 112 (73), 96 (15), 82 (15), 68 (15), 55 (40),
3
) δH/ppm: 0.90 (t, 3H, J = 7.6 Hz), 1.27 (sextet, 2H, J = 7.6
C
16
H19NO
2
: 257.1; found: 257.1(M , 100), 186.1 (50), 145.1 (30),
−
1
128 (35), 104 (60), 78 (20). IR (ATR), νmax/cm : 2958, 2871 (w,
aliphatic C-H stretching), 1354 (s, C-H symmetric bending), 1015 (w,
ether C-O symmetric stretching).
=
H27NO
6
ꢀꢀ ꢀꢀ ꢀ
(
4
Diethyl9-butyl-3,6,9,12-tetrahydro-2H-[1,4]dioxino[2 ,3 :4 ,
ꢀ
ꢀ
ꢀ
1 (33), 28 (33). IR (ATR), νmax/cm-1: 2934, 2872 (w, aliphatic
5 ] benzo[1 ,2 :6,7][1,4] dioxocino [2,3-c] pyrrole-8,10-
dicarboxylate (11): Under nitrogen atmosphere, diethyl 1-
butyl-3,4-dihydroxypyrrole-2,5-dicarboxylate (2) (1.00 g, 3.3 mmol)
C-H stretching), 1552, 1409, 1360 (m, aliphatic C-H bending), 1263,
1
180 (s, ether C-O symmetric stretching), 732.
Diethyl 2-butyl-5,10-dihydro-2H-benzo[6,7][1,4]dioxocino [2,
-c]pyrrole-1,3-dicarboxylate (8): Into a 250 ml, two-necked,
was dissolved in 15 ml of pre-dried DMF and heated in oil bath at
◦
3
120 C for 15 min. K
2
CO
3
(2.20 g, 15.8 mmol) was added to the
round-bottomed flask diethyl 1-butyl-3,4-dihydroxypyrrole-2,5-
dicarboxylate (2) (1.70 g, 5.68 mmol) was charged and dissolved
solution and stirred for a half hour. Then, 6,7-bis(bromomethyl)-2,3-
dihydrobenzo[b][1,4]dioxine (4) (1.28 g, 4.0 mmol) was subsequently
added and the mixture was stirred at the same temperature for an
additional 8 h. After the completion of the reaction, DMF was
evaporated under reduced pressure and the residue was poured into
ice-water. The crude product was washed with 0.1 N potassium
hydroxide solution to give diester derivative of the target monomer
(11) as light orange colored solid (1.14 g) in 75% yield (observed
in 20 ml of dry DMF under nitrogen atmosphere. The oil bath was
◦
warmed to 120 C. K
2
CO
3
(3.03 g, 21.8 mmol) was added over
the solution and stirred for an additional half hour. Afterward, 1,2-
bis(bromomethyl)benzene (3) (1.50 g, 5.68 mmol) was added and the
mixture was maintained at the same temperature for 6 h. After excess
of DMF was removed under reduced pressure, the resulting residue
was poured into ice-water and washed with 0.1 N potassium hydrox-
ide solution in order to remove unreacted starting material. The crude
product was crystallized from diethyl ether to give desired diester
derivative (8) as orange colored solid (1.78 g) in 78% yield (observed
◦
1
3
m.p: 132–134 C). H-NMR (400 MHz, CDCl ) δH/ppm: 0.88 (t, 3H,
J = 7.6 Hz), 1.26 (sextet, 2H, J = 7.8 Hz), 1.40 (t, 6H, J = 6.8 Hz),
1.59 (p, 2H, J = 7.6 Hz), 4.24 (s, 4H), 4.34 (q, 2H, J = 7.2 Hz), 4.53
(t, 2H, J = 7.8 Hz), 5.34 (s, 4H), 6.72 (s, 2H, arom.). MS (EI) m/z
◦
1
+
m.p: 65–68 C). H-NMR (400 MHz, CDCl
3
) δH/ppm: 0.87 (t, J =
), 1.24 (sextet, J = 7.9 Hz, 2H, butyl -CH ),
), 1.60 (p, J = 7.6 Hz, 2H, butyl
), 4.53 (t, J = 7.8 Hz,
), 5.48 (s, 4H), 7.22 (dd, 2H), 7.34 (dd, 2H). MS (EI) m/z
: 401.3; found: 401.3 (M+, 70), 356 (25),
44 (20), 328 (35), 300 (30), 282 (20), 272 (35), 245 (95), 226 (25),
70 (10), 104 (100), 78 (30). IR (ATR), νmax/cm-1: 2987–2870 (w,
(%) calcd. for C24
H29NO
8
: 459.2; found: 459.2 (M , 8), 414 (7), 386
7
.6 Hz, 3H, butyl -CH
3
2
(33), 358 (20), 340 (20), 330 (25), 247 (11), 162 (100), 147 (11),
106 (18), 78 (26). IR (ATR), νmax/cm-1: 2984-2872 (w, aliphatic
C-H stretching), 1703, 1682 (s, ester C = O stretching), 1509, 1439
(s, aliphatic C-H bending), 1300-1243 (s, ester C-O-C asymmetric
and symmetric stretching), 1156, 1042 (s, ether C-O symmetric
stretching), 884, 776.
1
.40 (t J = 6.8 Hz, 6H, ester -CH
3
-
2
CH
H, N-CH
2
2
), 4.33 (q, J = 7.2 Hz, 4H, ester -CH
2
(
3
1
%) calcd. for C22H27NO
6
ꢀ
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ꢀ
9-Butyl-3,6,9,12-tetrahydro-2H-[1,4]dioxino[2 ,3 :4 ,5 ]benzo
ꢀ
ꢀ
aliphatic C-H stretching), 1709, 1689 (s, ester C-O stretching), 1438
[1 ,2 :6,7][1,4] dioxocino[2,3-c]pyrrole-8,10-dicarboxylic acid
(
(
m, aliphatic C-H bending), 1312 (m, C-H symmetric bending), 1245
s, ester C-O-C asymmetric stretching), 1153, 1039 (s, ester C-O-C
ꢀꢀ ꢀꢀ ꢀ ꢀ
9-butyl-3,6,9,12-tetrahydro-2H-[1,4]dioxino[2 ,3 :4 ,5 ]
symmetric stretching), 1025 (s, ether C-O symmetric stretching).
-Butyl-5,10-dihydro-2H-benzo[6,7][1,4]dioxocino[2,3-c]
pyrrole-1,3-dicarboxylic acid (9): Diethyl 2-butyl-5,10-dihydro-
H-benzo[6,7][1,4]dioxocino[2,3-c]pyrrole-1,3-dicarboxylate (8)
0.78 g, 1.94 mmol) was dissolved in 10 ml ethanol, followed by
2
2
(
the addition of KOH (85%, 0.33 g, 5.8 mmol), 5 ml EtOH and 1
ml H2O. The mixture was refluxed in hot water bath for 5 hours.
Unreacted diester (8) was eliminated by extraction with diethyl
ether and then the residue was poured into the crushed ice-water
solution. The water phase was acidified with concentrated HCl (pH:
2
). The resulting cream colored solids were filtered to yield 0.65
C-H stretching), 1664 (s, acid C = O stretching), 1453 (m, aliphatic
C-H asymmetric bending), 1439 (m, C-H symmetric bending), 1303
(s, C-O asymmetric stretching), 1053 (m, C-O symmetric stretching).
g (97%) of 2-butyl-5,10-dihydro-2H-benzo[6,7][1,4]dioxocino[2,3-
c]pyrrole-1,3-dicarboxylic acid (9) (observed m.p: 148–149 C). IR
◦
ꢀꢀ ꢀꢀ ꢀ ꢀ
(
ATR), νmax/cm-1: 3500-2500 (O-H stretching), 3063 (w, aromatic
9-Butyl-3,6,9,12-tetrahydro-2H-[1,4]dioxino[2 ,3 :4 ,5 ]
ꢀ
ꢀ
C-H stretching), 2969–2870 (w, aliphatic C-H stretching), 1687 (s,
acidic C-O stretching), 1439 (m, C-H symmetric bending), 1343 (m,
C-H asymmetric bending), 1270, 1253, 1239 (s, C-O asymmetric
bending), 1041 (m, C-O symmetric stretching).
benzo[1 ,2 :6,7][1,4] dioxocino[2,3-c]pyrrole (13): The correspond-
ing dicarboxylic acid derivative; 9-butyl-3,6,9,12-tetrahydro-2H-[1,
ꢀ
ꢀ
ꢀꢀ
ꢀ
ꢀ
ꢀ
ꢀ
4]dioxino[2 ,3 :4 ,5 ]benzo[1 ,2 :6,7][1,4]dioxocino[2,3-c]pyrrole-8,
10-dicarboxylic acid (12) (0.50 g, 1.24 mmol) was dissolved in
5 ml triethanolamine. The solution was stirred under a nitrogen
2
-Butyl-5,10-dihydro-2H-benzo[6,7][1,4]dioxocino[2,3-c]pyr-
◦
role (10): 2-Butyl-5,10-dihydro-2H-benzo[6,7][1,4]dioxocino[2,3-
c]pyrrole-1,3-dicarboxylic acid (9) (0.50 g, 1.45 mmol) was dissolved
in 5 ml triethanolamine. The solution was stirred under nitrogen
atmosphere in a preheated oil bath at 135 C. The reaction was mon-
itored by TLC and completed in 30 min. The mixture allowed to cool
flow in a preheated oil bath at 140 C. The reaction was complete
in approximately 30 min as monitored by TLC. The flask content
allowed to cool down to room temperature, and mixed with ice-water
and then, extracted with DCM, washed with brine and water, respec-
tively. DCM was evaporated under reduced pressure after drying the
◦