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doi.org/10.1002/open.202000273
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mixture was added dropwise to the flask with vigorous stirring for
1 h and then stirred for 2 h until the end of adding the mixture.
Subsequently, 8.6 g (0.057 mol) BIT was added to the above mixture
and refluxed for 2 h. The mixture was then cooled to room
temperature and washed twice with deionized water, and the pH
was adjusted to neutral with a 10% sodium bicarbonate solution.
The organic phase was separated and dried overnight with
magnesium sulfate anhydrous, and filtered under vacuum. After the
removal of the solvent, the products were purified by flash column
chromatography on silica gel, eluting with mixtures of ethyl acetate
microbial adhesion, which indicated that the copolymer could
be used as a potential marine antifouling coating.
Experimental Section
Materials
1,2-Benzisothiazolin-3-one (BIT), allylamine, trimethylamine (Et3N),
triphosgene (BTC), MMA, acrylic acid (AA), BA, zinc dibenzoate, 2,2-
azobisisobutyronitrile (AIBN), N,N-dimethylformamide (DMF), meth-
ylbenzene, acryloyl chloride, dichloromethane (DCM), and tetrahy-
drofuran (THF) were purchased from Tianjin Fuyu Fine Chemical
Co., Ltd, and were used without further purification. Flash column
chromatography was performed on gel (100–200 mesh, Qingdao
Haiyang Chemical Co. Ltd). Thin layer chromatography (TLC)
analysis was conducted on GF254 plates using ethyl acetate and
petroleum ether mixtures as eluent. The seawater was collected
from the coast near the Yingbin Peninsula in Hainan Province, then
filtered, boiled, and disinfected before use.
1
and petroleum ether. Yield: 80%. H NMR(400 MHz, CDCl3), δ: 9.0(s,
1H, NH); 8.03(d, J=8.0 Hz, 1H); 7.70(t, J=8.0 Hz, 1H); 7.58(d, J=
8.0 Hz, 1H); 7.43(t, J=8.0 Hz, 1H); 5.89–5.99 (m, 1H, -CH=); 5.31(dd,
J=16.8, 1.2 Hz, 1H); 5.21(dd, J=10.4, 1.2 Hz, 1H); 4.07–4.10(m, 2H).
IR (KBr): ν(cmÀ 1): 1660 (C=C), 3011 (=CÀ H), 3085 (=CH2); 1702 (C=O);
3378, 1660 (À CONHÀ ).
Heterocyclic Monomers (HCM) Synthesis
As shown in Scheme 2, 0.02 mol heterocyclic compound and 50 mL
dichloromethane were mixed in
a
100-mL three-neck flask
°
equipped with a stirrer and a thermometer and cooled to 0–5 C
using an ice-water bath. Then, 0.02 mol triethylamine was added as
an acid acceptor. Acryloyl chloride (0.024 mol) was added dropwise
Physical Properties
Hydrogen nuclear magnetic resonance (1H NMR) spectra were
recorded on a 400-MHz Bruker spectrometer using tetrameth-
ylsilane (TMS) as the internal standard. FT-IR spectra were recorded
at room temperature in the frequency range of 4000–400 cmÀ 1 on a
PerkinElmer spectrum 100 FT-IR spectrometer using KBr pellets. The
average molecular weight and molecular weight distribution were
obtained by gel permeation chromatography (Waters 2414). The
°
to the flask in an ice bath with vigorous stirring for 1 h at 0–5 C
and then stirred for 2 h at room temperature.
The mixture was extracted with 20 mL ethyl acetate, washed first
with 20 mL saturated salt water, and then washed twice with 20 mL
deionized water. The organic phase was separated and dried over
anhydrous magnesium sulfate overnight and filtered under vac-
uum. After the removal of the solvent, the products were purified
by flash column chromatography on silica gel eluting with a 10:1
petroleum ether:ethyl acetate mixture.
°
experiment was conducted in tetrahydrofuran (THF) at 35 C using
a WAT044225 column (7.8×300 mm) at a flow rate of 1.0 mL/min.
The instrument was calibrated using polystyrene (PS) standards.
The glass transition temperature (Tg) was determined using differ-
ential scanning calorimetry (DSC, Q20, TA instrument). A hermetic
aluminum pan was used for loading samples to prevent overflow
during the heating process and the heating rate was 10 C/min
under a nitrogen flow of 50 mL/min.
N-(benzo[d]thiazol-2-yl)acrylamide (5a), Yield: 75%. 1H-NMR
(400 MHz, DMSO-d6), δ 12.63(s, 1H, NH); 8.02 (d, J=8.0 Hz, 1H); 7.79
(d, J=8.0 Hz, 1H); 7.47 (t, J=7.6 Hz, 1H); 7.34 (t, J=7.6 Hz, 1H); 6.62
(dd, J=17.2, 10.0 Hz, 1H); 6.48 (dd, J=17.2, 2.0 Hz, 1H); 5.99 (dd, J=
10.0, 2.0 Hz, 1H). IR (KBr): ν(cmÀ 1): 3438, 1586 (À CONHÀ ), 1713
(C=O), 1610 (C=C).
°
N-(thiazol-2-yl)acrylamide (5b), Yield: 80%. 1H-NMR (400 MHz,
DMSO-d6), δ 12.38 (s, 1H, NH); 7.53 (d, J=3.2 Hz, 1H); 7.27(d, J=
3.2 Hz, 1H); 6.56 (dd, J=17.2, 10.0 Hz, 1H); 6.42 (dd, J=17.2, 2.0 Hz,
1H); 5.92 (dd, J=10.0, 2.0 Hz, 1H). IR (KBr): ν(cmÀ 1): 3316, 1487
(À CONHÀ ), 1710 (C=O), 1642 (C=C).
N-(pyridin-2-yl)acrylamide (5c), Yield: 97%. 1H-NMR (400 MHz,
DMSO-d6), δ 10.74 (s, 1H, NH); 8.35 (d, J=4.8 Hz, 1H); 8.23 (d, J=
8.4 Hz, 1H); 7.80 (t, J=7.6 Hz, 1H); 7.10–7.13 (m, 1H); 6.65 (dd, J=
16.8, 10.0 Hz, 1H); 6.34 (dd, J=16.8, 2.0 Hz, 1H); 5.79 (dd, J=10.0,
2.0 Hz, 1H). IR (KBr): ν(cmÀ 1): 3442, 1490 (À CONHÀ ), 1712 (C=O),
1500 (C=C).
N-allyl (1,2-Benzo[d]isothiazol-3(2H)-one) Carboxamide
Monomer (NCM) Synthesis
As shown in Scheme 1, BTC 2 and allylamine 1 were reacted in
toluene in the presence of Et3N to produce N-allyl-carbamic
chloride 3. Then, intermediate 3 reacted with BIT to afford N-allyl-
(1,2-Benzo[d] isothiazol-3(2H)-one) carboxamide 4. Precisely, 9.9 g
BTC (0.033 mol) and 90 mL toluene were mixed in a 250-mL three-
neck flask equipped with a stirrer and a thermometer, and cooled
°
to 0–5 C in an ice-water bath until BTC 2 dissolved completely.
Furthermore, 8.6 g (0.15 mol) allylamine were mixed with 10 mL
toluene and a small amount of triethylamine (4–5 d), and the
N-(5-methylpyridin-2-yl)acrylamide (5d), Yield: 92%. 1H-NMR
(400 MHz, DMSO-d6), δ 10.65 (s, 1H, NH); 8.17 (d, J=2.0 Hz, 1H);
8.11 (d, J=8.4 Hz, 1H); 7.62 (dd, J=8.4, 2.0 Hz, 1H); 6.3 (dd, J=16.8,
Scheme 1. Synthesis of 3-oxo-N-allyl-1,2-benzisothiazole-2(3H)-carboxamide
monomers.
Scheme 2. Synthesis of N-heterocyclic acrylamide monomers.
ChemistryOpen 2021, 10, 523–533
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