ARTICLE
under reduced pressure. 4-tert-Butoxystyrene (tBS, 99%)
was passed through an inhibitor-removing column before
use. a,a0-Azoisobutyronitrile (AIBN, 98%) was recrystallized
from methanol. Xylene (Fisher Chemicals, 99%), tetrahydro-
furan (THF, 99.9%), N,N-dimethylformamide (DMF, 99%),
methanol (99.9%), and 1,4-dioxane (>99%) were purified
and dried applying standard procedures. Di-tert-butyl dicar-
bonate (Fluka, >98%), 3-chloropropylamine hydrochloride
(98%), 3-bromopropanesulfonic acid sodium salt (>99%),
2-chloro-N,N-dimethylethylamine hydrochloride (98%), N,N,
N0,N00,N00-pentamethyldiethylenetriamine (PMDETA, 99%),
propargyl bromide (71.7 wt % in toluene), 18-crown-6
(99%), potassium carbonate (99%), tetrabutylammonium
iodide (TBAI, ꢀ99%), potassium iodide (ꢀ99%), sodium az-
ide (99%), copper(I) bromide (CuBr, 98%), and 1,3-propane-
sultone (PrS, 98%) were used as received.
Synthesis of 3-Azidopropanesulfonic Acid Sodium
Salt (APS)
Sodium azide (0.72 g, 11.1 mmol) and 3-bromopropanesul-
fonic acid sodium salt (1 g, 4.44 mmol) were mixed in 30
mL of DMF and stirred under nitrogen overnight. The reac-
tion mixture was concentrated, filtered, and most of the sol-
vent was removed on a rotary evaporator. The product was
precipitated in THF and dried. Yield: 0.8 g (96%). FTIR
(cmꢃ1): 1055 and 1208 (O¼¼S¼¼O), 2103 (Nꢃ¼¼Nþ¼¼N). 1H-
NMR (300 MHz, D2O, d, ppm): 3.51 (Nꢃ¼¼Nþ¼¼NACH2), 3.02
(CH2ASO3ꢃ), 2.04 (CH2ACH2ACH2).
Synthesis of tert-Butyl N-(3-Azidopropyl)
carbamate (Boc-APA)
Sodium azide (0.84 g, 12.91 mmol) and tert-butyl N-(3-chlor-
opropyl) carbamate (1 g, 5.16 mmol) were stirred in 35 mL
of DMF at 90 ꢁC overnight under nitrogen. Most of the sol-
vent was evaporated. The residue was diluted with 35 mL of
dichloromethane and extracted with water (3 ꢄ 50 mL). The
organic layer was dried over sodium sulfate, filtered, and the
solvent was evaporated. Yield: 0.86 g (84%). FTIR (cmꢃ1):
1516 (NAH—urethane, amide II), 1686 (C¼¼O—urethane,
amide I), 2093 (Nꢃ¼¼Nþ¼¼N), 3347 (NAH). 1H-NMR
(300 MHz, CDCl3, d, ppm): 4.66 (NH), 3.35 (CH2AN¼¼Nꢃ¼¼Nþ),
3.21 (NHACH2), 1.78 (CH2ACH2ACH2), 1.44 (CH3)3.
Poly[(4-hydroxystyrene)-ran-styrene] (PS-ran-PHS)
Poly[(4-hydroxystyrene)-ran-styrene] (PS-ran-PHS) was syn-
thesized by free radical polymerization of styrene (S) and
4-tert-butoxystyrene (tBS) in xylene at 65 ꢁC followed by
deprotection to hydroxyl derivatives as previously
described.17 Random copolymer with composition of ꢂ20/
80 mol % (HS/S) was obtained. SEC in THF (vs. polystyrene
standards): Mn ¼ 15,000, Mw/Mn ¼ 1.72. FTIR (cmꢃ1): 3349
(OAH), 1225 (C6H4AO). 1H-NMR (300 MHz, DMSO-d6, d,
ppm): 9.0 (C6H4AOH), 7.25–6.85 (3H, C6H5), 6.85–6.15 (2H,
C6H5 þ C6H4AOH), 2.2–1.65 (CHAC6H4 þ CHAC6H5), 1.65–
1.1 (CH2ACHAC6H4 þ CH2AC6H5).
Synthesis of 2-Azido-N,N-dimethylethylamine (ADMEA)
The synthetic procedure was adapted from the literature.24
Sodium azide (2.71 g, 41.65 mmol) and 2-chloro-N,N-dime-
thylethylamine hydrochloride (2 g, 13.88 mmol) were dis-
ꢁ
solved in 50 mL of water and stirred at 80 C for 16 h. The
reaction mixture was concentrated to ꢂ1/3 of the initial vol-
ume (The temperature of the water bath should not exceed
50 ꢁC). Then it was cooled down (ice bath) and 50 mL of
diethyl ether was added followed by the addition of 2 g of
potassiumꢁ hydroxide on portions keeping the temperature
below 10 C. The mixture was stirred vigorously for 30 min.
The organic layer was separated and the aqueous phase was
extracted with diethyl ether (2 ꢄ 25 mL). The combined or-
ganic layers were dried over sodium sulfate and the solvent
was evaporated. Yield: 1.1 g (70%). FTIR (cmꢃ1): 2107
(Nꢃ¼¼Nþ¼¼N), 2772 and 2833 (ANA (CH3)2). 1H-NMR (300
MHz, DMSO-d6, d, ppm): 3.33 (Nꢃ¼¼Nþ¼¼NACH2), 2.44
(CH2AN), 2.18 (NA(CH3)2).
Poly[4-(prop-2-ynoxy)styrene-ran-styrene] (PS-ran-PAS)
Poly[4-(prop-2-ynoxy)styrene-ran-styrene] (PS-ran-PAS) was
obtained from PS-ran-PHS through a Williamson etherifica-
tion with propargyl bromide.23 SEC in THF (vs. polystyrene
standards): Mn ¼ 18,600, Mw/Mn ¼ 1.73. FTIR (cmꢃ1): 3297
(CBCAH), 1216 (C6H4AO). 1H-NMR (300 MHz, DMSO-d6, d,
ppm): 7.3–6.85 (3H, C6H5), 6.85–6.15 (2H, C6H5
C6H4AOACH2), 4.67 (C6H4AOACH2), 3.51 (CH2AC(H), 2.3–
þ
1.65 (CHAC6H4 þ CHAC6H5), 1.65–1.0 (CH2ACHAC6H4
CH2AC6H5).
þ
Synthesis of tert-Butyl N-(3-Chloropropyl) carbamate
(Boc-CPA)
Typically, 5 g of di-tert-butyl dicarbonate (22.91 mmol) and
2.98 g (22.91 mmol) of 3-chloropropylamine hydrochloride
were dissolved in 10 mL of solvent mixture THF/water (1:1,
v/v). The pH was adjusted to ꢂ9 by the addition of 1 M
aqueous NaOH and the reaction mixture was stirred over-
night at room temperature. The solution was acidified to pH
ꢂ2 to 3 (10% KHSO4) and the product was extracted with
dichloromethane. The organic layer was washed several
times with water, dried over Na2SO4, filtered, and the sol-
vents were evaporated. Yield: 3.78 g (85%). FTIR (cmꢃ1):
1516 (NAH, urethane, amide II), 1686 (C¼¼O—urethane, am-
Synthesis of Basic and Acidic Copolymers via
Williamson-Type Etherification or Sulfoalkylation
Polystyrene-Based Copolymer with Randomly Distributed
Primary Amine Pendant Groups (PS-ran-PAPS)
A solution of PS-ran-PHS (1 g, 1.95 mmol OH-groups), Boc-
CPA (0.56 g, 2.9 mmol), potassium carbonate (0.67 g,
4.88 mmol), 18-crown-6 (0.076 g, 0.29 mmol), TBAI (0.11 g,
029 mmol), and potassium iodide (0.032 g, 0.195 mmol) in
15 mL of THF was refluxed for 24 h. The solution was fil-
tered and washed consecutively with saturated aqueous so-
dium hydrogen carbonate and brine. Then, it was dried over
magnesium sulfate, concentrated and the polymer was pre-
cipitated in methanol. Yield: 1 g (77%). 1H-NMR (300 MHz,
CDCl3, d, ppm): 7.25–6.80 (3H, C6H5), 6.80–6.20 (2H, C6H5 þ
1
ide I), 3347 (NAH). H-NMR (300 MHz, CDCl3, d, ppm): 4.67
(NH), 3.58 (CH2ACl), 3.26 (NHACH2), 1.96 (CH2ACH2ACH2),
1.43 (CH3)3.
POLYSTYRENE-BASED RANDOM COPOLYMERS, DIMITROV, JANKOVA, AND HVILSTED
2045