JOURNAL OF POLYMER SCIENCE PART A: POLYMER CHEMISTRY DOI 10.1002/POLA
triethylamine (1.18 mL, 8.53 mmol) in 20 mL of dry THF at
0
Prop-2-ynyl 4-(11-(6-(3,3-dimethylbutanamido)pyridin-
2-ylamino)-11-oxoundecyloxy) Benzoate (6)
ꢁC. The solution was stirred at ambient temperature for
16 h. The precipitate formed during the reaction was filtered
off and the solvent was subsequently removed under
reduced pressure. The crude product was purified by column
chromatography [dry packed column; silica gel, CH2Cl2/ethyl
acetate (4:1) eluent], giving a white solid 3 after removal of
solvent (3.14 g, yield 92%).
Compound 5 (0.7 g, 1.36 mmol) was dissolved in 15 mL of
dry DMF. Propargyl bromide (0.202 g, 1.71 mmol) and
K2CO3 (0.375 g, 2.72 mmol) were subsequently added. The
reaction was stirred at ambient temperature for 4 h. The
precipitate formed during the reaction was removed by fil-
teration. The filtrate was dried using a rotary evaporator and
the crude product obtained was dissolved in DCM. The or-
ganic phase was washed with water, dried over Na2SO4, fil-
tered, dried using a rotary evaporator, and then dried under
vacuum. Purification by recrystallization from n-hexane gave
compound 6 as a white solid (0.71 g, 94%).
1H NMR (400 MHz, DMSO-d6) d 1.00 (s, 9H), 1.27 (bs, 14H),
1.55 (bm, 2H), 1.68–1.73 (t, 2H), 2.29 (s, 2H), 2.35–2.41 (t,
2H), 3.60 (s, 1H), 4.03 (s, 2H), 4.91 (s, 2H), 7.02–7.06 (d,
2H), 7.72 (s, 3H), 7.89–7.92 (d, 2H), 9.89 (s, 1H), 10.00 (s,
1H). 13C NMR (100 MHz, DMSO-d6) d 24.89, 25.34, 28.42,
28.48, 28.62, 28.65, 28.71, 28.84, 29.44, 30.76, 35.97, 48.94,
67.80, 77.65, 78.51, 108.92, 114.09, 120.84, 139.68, 150.14,
150.24, 162.80, 164.54, 170.73, 172.09. ESI-MS (MþNa)þ
C32H43N3O5 theoretical: 549.32, experimental: 549.27.
1H NMR (400 MHz, DMSO-d6) d (ppm) 1.00 (s, 9H), 1.25
(brs, 14H), 1.55 (bs, 2H), 1.80–1.74 (q, 2H), 2.29 (s, 2H),
2.35–2.41 (t, 2H), 3.53 (t, 2H), 7.72–7.74 (bs, 3H), 9.89 (s,
1H), 10.00 (s, 1H). 13C NMR (100 MHz, DMSO-d6) d 24.89,
25.34, 28.42, 28.48, 28.62, 28.65, 28.71, 28.84, 29.44, 30.76,
35.97, 49.04, 60.67, 108.60, 141.79, 148.76, 171.73, 173.07.
ESI-MS (MþNa)þ C22H36BrN3O2 theoretical: 453.20, experi-
mental: 453.17.
Methyl 4-(11-(6-(3,3-dimethylbutanamido)pyridin-2-
ylamino)-11-oxoundecyloxy) Benzoate (4)
Compound 3 (1.5 g, 3.40 mmol) was dissolved in 30 mL of
DMF. Methyl 4-hydroxybenzoate (0.622 g, 4.09 mmol) and
K2CO3 (0.847 g, 6.13 mmol) were subsequently added to the
solution. The reaction mixture was stirred overnight at ambi-
ent temperature. After this time, the reaction mixture was
poured into water and extracted with a mixture of DCM and
diethyl ether (1:1). The organic phase was washed with
water, dried over Na2SO4, and concentrated. The product
was purified by recrystallization from ethyl acetate affording
a white solid 4 (1.494 g, 86%).
1H NMR (400 MHz, CD2Cl2) d 1.03 (s, 9H), 1.6 (bs, 14H),
1.63 (bm, 2H), 1.76 (brm, 2H), 2.17 (s, 2H), 2.30–2.33 (t,
2H), 3.80 (s, 3H), 3.96 (s, 2H), 6.84–6.88 (d, 2H), 7.63 (bm,
3H), 7.89–7.92 (bm, 4H). 13C NMR (100 MHz, DMSO-d6) d
24.89, 25.34, 28.42, 28.48, 28.62, 28.65, 28.71, 28.84, 29.44,
37.82, 39.82, 51.83, 68.17, 109.28, 109.32, 114.07, 122.33,
131.56, 162.96, 166.94. ESI-MS (MþNa)þ C30H43N3O5 theo-
retical: 525.32, experimental: 525.29.
Synthesis of a-Thymine Functional PS (Thy-PS-Br) (8)
Styrene (8.0 mL, 6.98 mmol), PMDETA (0.073 mL, 0.349
mmol), and 7 (0.155 g, 0.349 mmol) in 2 mL of anisole were
added to a 50-mL Schlenk tube. The reaction mixture was
degassed via three successive freeze–pump–thaw cycles and
left under argon. CuBr (0.050 g, 0.349 mmol) was added to
the solution under argon. The tuꢁbe was subsequently sealed
and placed in an oil bath at 110 C for 45 min. The polymer-
ization mixture was rapidly cooled in an ice bath, diluted
with THF, and passed through an alumina column to remove
the catalyst. The solvent was removed under reduced pres-
sure and the remaining crude product was subsequently
diluted with DCM (50 mL) and washed with 0.1 M EDTA
(10 mL) solution to remove any remaining Cu, which might
be complexed to the recognition unit. The organic phase was
dried over Na2SO4, concentrated, and precipitated in 80 mL
methanol twice. The polymer was dried for 24 h under vac-
uum to give a-thymine functional poly(sytrene) as a white
4-(11-(6-(3,3-Dimethylbutanamido)pyridin-2-ylamino)-
11-oxoundecyloxy)benzoic Acid (5)
NaOH (1 N, 10 mL) was added to a solution of compound 4
(1 g, 1.95 mmol) in THF and MeOH (2:1, 30 mL). The solu-
tion was stirred at ambient temperature for 5 h and subse-
quently concentrated to a volume of 15 mL. The reaction
mixture was poured into 150 mL of water and concentrated
HCl was added dropwise to generate a white precipitate,
which was filtered, washed with water, and dried under vac-
uum to give compound 5 as a white solid (0.914 g, 94%).
solid (0.545 g). ([M]0/[I]0 ¼ 200, [I]0:[CuBr]0:[PMDETA]0
¼
1:1:1). Mn,NMR ¼ 8500 Da, Mn,SEC ¼ 8600 Da, PDI ¼ 1.05,
end group fidelity (with respect to thymine and Br) close to
98%.
Synthesis of a-Thymine Functional PS with Azide
Endgroup (Thy-PS-N3) (9)
The bromide of Thy-PS-Br 8 was converted to the azide
functionality with NaN3 in DMF at ambient temperature fol-
lowing a literature procedure.27 Attenuated total reflectance-
1H NMR (400 MHz, DMSO-d6) d 1.00 (s, 9H), 1.27 (bs, 14H),
1.55 (bm, 2H), 1.68–1.73 (t, 2H), 2.28 (s, 2H), 2.34–2.40 (t,
2H), 4.01 (s, 2H), 6.97–7.00 (d, 2H), 7.71 (s, 3H), 7.85–7.87
(d, 2H), 9.89 (s, 1H), 10.00 (s, 1H), 12.58 (s, 1H). 13C NMR
(100 MHz, DMSO-d6) d 24.89, 25.34, 28.42, 28.48, 28.62,
28.65, 28.71, 28.84, 29.44, 30.76, 35.97, 48.94, 67.64,
108.92, 114.09, 122.65, 139.68, 150.14, 150.24, 162.19,
166.90, 170.73, 172.09. ESI-MS (MþNa)þ C29H42N3O5 theo-
retical: 511.3, experimental: 511.28.
infra red (ATR-IR) (cmꢂ1): 2095 (N3 stretching). Mn,NMR
8500 Da, Mn,SEC ¼ 8600 Da, PDI ¼ 1.05.
¼
Synthesis of a,x-Donor–Acceptor Single Chain
PS (10) (Thy-PS-DAP)
Compound 9 (0.2 g, 0.023 mmol), compound 6 (0.039 g,
0.07 mmol), copper (II) sulfate pentahydrate (0.017 g, 0.07
mmol), and sodium ascorbate (0.014 g, 0.07 mmol) were
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