Synthesis of new phosphonated monomers

Article abstract of DOI:10.1080/10426500490494723

Two phosphonated methacrylates containing urethane group were synthesized by reacting the isocyanatoethyl methacrylate (IEM; CH₂=C(CH ₃)COO(CH₂)₂NCO) and a phosphonated alcohol (OH(CH₂)_xP(O)(OMe)₂, x = 1 or 2), and they are hydrolyzed into mono- and diacid monomers. All these products were characterized in ¹H and ³¹P NMR. Unlike usual methods (esterification and transesterification), these syntheses were quantitative and easy to realize.

Full text of DOI:10.1080/10426500490494723

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SYNTHESIS OF NEW
PHOSPHONATED MONOMERS
Bérengère Rixens a , Gilles Boutevin a , Ahmed
Boulahna a , Yves Hervaud a & Bernard Boutevin a
a Laboratoire de Chimie Macromoléculaire, Ecole
Nationale Supérieure de Chimie de Montpellier ,
Montpellier, France
Published online: 16 Aug 2010.
To cite this article: Bérengère Rixens , Gilles Boutevin , Ahmed Boulahna , Yves
Hervaud & Bernard Boutevin (2004) SYNTHESIS OF NEW PHOSPHONATED MONOMERS,
Phosphorus, Sulfur, and Silicon and the Related Elements, 179:12, 2617-2626, DOI:
10.1080/10426500490494723
To link to this article: http://dx.doi.org/10.1080/10426500490494723
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Phosphorus, Sulfur, and Silicon, 179:2617–2626, 2004
ꢀC
Copyright Taylor & Francis Inc.
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426500490494723
SYNTHESIS OF NEW PHOSPHONATED MONOMERS
Be´renge`re Rixens, Gilles Boutevin, Ahmed Boulahna,
Yves Hervaud, and Bernard Boutevin
Laboratoire de Chimie Macromole´culaire, Ecole Nationale
Supe´rieure de Chimie de Montpellier, Montpellier, France
(Received May 11, 2004; accepted June 1, 2004)
Two phosphonated methacrylates containing urethane group were
synthesized by reacting the isocyanatoethyl methacrylate (IEM;
CH2 C(CH3)COO(CH2)2NCO) and
a
phosphonated alcohol
(OH(CH )xP(O)(OMe)2, x = 1 or 2), and they are hydrolyzed into
mono- a2nd diacid monomers. All these products were characterized
in 1H and 31P NMR. Unlike usual methods (esterification and
transesterification), these syntheses were quantitative and easy to
realize.
Keywords: Hydrolysis; isocyanatoethyl methacrylate; phosphonated
alcohols; phosphonated monomers
INTRODUCTION
Phosphonated monomers and polymers are of interest in a va-
riety of applications, including flame-retardant, anticorrosive, and
adhesion. Indeed, the stability toward hydrolysis of phospho-
nated polymers is better than that of phosphated polymers be-
cause P C bonds are preferred. Some phosphonated monomers,
such as CH2 C(R1)COO(CH2)nP(O)(OR2)2 with R1 = H or CH3,1,2
CH2 C(CH3)COO CH2CHOHCH2 P(O)(OR2)2,3 or carbamoyl phos-
phonates obtained by reaction between an isocyanate and a dialkyl
phosphite,4–6 have been described previously.
The aim of this study is to synthesize new polymerizable monomers
bearing phosphonated functions, and to decrease the synthesis steps
and to increase the yield. A direct reaction of a methacrylate isocyanate
with a phosphonated alcohol is described in this article.
Address correspondence to Bernard Boutevin, Ecole Nationale Supe´rieure,
Heterochimie Mol. et Macromol, 8, rue de l’Ecole Normale, Montpellier, Cedex 5 F-34296,
France. E-mail: boutevin@cit.enscm.fr
2617

2618
B. Rixens et al.
RESULTS AND DISCUSSION
Our aim is to synthesize new phosphonated monomers by reaction be-
tween an isocyanate group and an alcohol group. This type of reaction,
widely described in the literature, can be catalyzed by tertiary amine or
organic metallic compounds such as dibutyl tin dilaurate (DBTDL)7–10
or SmI2.11 This reaction can be also realized without catalyst and
with12–15 or without solvent.16,17 We decided to work with an isocyanate
bearing a methacrylate function, i.e., isocyanatoethyl methacrylate
(IEM). Reacting IEM with a dialkyl phosphite led to a monomer with
the following structure: CH2 C(CH3)COO-(CH2)2-NH CO P(O)(OR)2
(R Me, Et).5 Some earlier papers described the reaction between IEM
and sugar18 or hydroxyethyl methacrylate,10 thus the reaction with this
isocyanate and a phosphonated alcohol was studied. Moreover the addi-
tion of hydroxyphosphonate to phenyl thiocyanate19,20 can be realized
without catalyst with acrylonitrile as solvent. So, according to these
papers we chose to synthesize the monomers without catalyst and with
or without solvent.
For the first time, the synthesis of two phosphonated alcohols,
with one or two carbon spacer, is described. Then reactions with the
methacrylate are studied.
Synthesis of Phosphonated Precursors
Synthesis of Dimethyl Hydroxymethylphopsphonate
Alcohol in C1
Recent papers from our laboratory described this alcohol synthesis.21
Thus it was achieved as already described21,22 via a Pudovik23 reaction
using dimethyl hydrogenophosphonate (HPO(OCH3)2), paraformalde-
hyde, and anhydrous potassium carbonate as catalyst.
Synthesis of Dimethyl 2-Acetoxyethylphosphonate:
Alcohol in C2
The literature described this alcohol synthesis in two steps: a telom-
erization of vinyl acetate with dialkyl hydrogenophosphonate as trans-
fer agent.24–26 followed by an acetate function cleavage.27 Recent works
realized by our group22,28 allowed the optimization of this reaction.
Monomer Synthesis
The phosphonated monomers were always synthesized with reagents in
stoichiometric conditions. This synthesis can be realized with or without

Phosphonated Monomers
2619
solvent, leading in both cases to a quantitative yield. Two syntheses are
described in this article: the first one with solvent with C1 alcohol and
the second one without solvent with C2 alcohol. These monomers were
then hydrolysed, leading to mono- and diacid compounds.
Monomer Synthesis with C1 Alcohol in Solvent
To avoid the urea formation, the mixture had to be completely dehy-
drated before reaction between IEM and an alcohol.
An azeotropic evaporation was realized during 30 min (70◦C/160 mm
Hg) to eliminate the water contained in phosphonated alcohol. Then
IEM was added drop by drop under inert atmosphere. The reaction
time was 10 h at room temperature, and the monomer was obtained
with quantitative yield (Figure 1).
This reaction was analyzed by infrared spectroscopy. The NCO (ν =
2160 cm−1) and OH (ν = 3450 cm−1) bands totally disappeared and two
new bands at 1730 cm−1 and 3200 cm−1 appeared, respectively charac-
terizing a carbonyl and NH urethane functions, proving a quantitative
reaction.
The 1H NMR spectrum (Figure 2) showed two doublets at
3.6 ppm and 4.3 ppm, respectively corresponding to phosphonic ester
(PO(OCH3)2) and CH2 in the α position of the phosphonated group. It
also characterized the methacrylic protons, the NH urethane group, and
the methacrylic methyl. The 31P NMR spectrum proved the quantita-
tive reaction. Indeed, the alcohol signal at 26 ppm totally disappeared
and a singlet appeared at 23 ppm, corresponding to the monomer.
Monomer Synthesis with C2 Alcohol
This reaction was performed without solvent. Phosphonated alcohol
and IEM were introduced under inert atmosphere in stoichiometric
conditions. After 6 h of reaction, the monomer was obtained with quan-
titative yield (Figure 3).
The phosphonated monomer (IEMPC2) was characterized by 1H and
1
31P NMR spectroscopy. The H NMR (Figure 4) showed a doublet cor-
responding to phosphonic esters, a doublet of triplet for methylene in α
position of phosphonated group, and the triplet of NH. The character-
istic methacrylic protons appeared as two singlets and the methacrylic
FIGURE 1 Synthesis of phosphonated monomer IEMPC1.

2620
B. Rixens et al.
FIGURE 2 1H NMR spectrum in CDCl3 of IEMPC1.
methyl as a singlet. Moreover, the protons of the phosphonated alcohol
signal totally disappeared. The 31P NMR spectrum proved the quanti-
tative reaction: a singlet appeared at 30.4 ppm, corresponding to the
monomer.
The reaction rate was followed by 31P NMR. The reaction was com-
plete after 6 h. The results are summarised in Table I. Figure 5 shows
the monomer formation versus time. The reaction was fast at the be-
ginning; 68.5% of conversion was obtained after 1 h. Then the reaction
slowed down, possibly due to an increase of the viscosity. The reaction
was quantitative after 6 h.
Hydrolysis of Phosphonic Ester Functions of Monomers
Two cleavage methods could be used to hydrolyze a phosphonic ester
(Figure 6). By using Sodium Iodide a monodealkylation of phosphonic
esters2,29 led to a salt. This salt acidified by an ionic exchange resin,
FIGURE 3 Synthesis of phosphonated monomer IEMPC2.

Phosphonated Monomers
2621
6
TABLE I Rate Reaction of the IEMPC2 Synthesis
Reaction time (h)
0
1
2
3
4
5
% molar of phosphonated alcohol
% molar of monomer IEMPC2
100
0
31.5
68.5
23.1
76.9
17.7
82.3
12.3
87.7
7.1
92.9
2.7
97.3
FIGURE 4 1H NMR spectrum of IEMPC2.
FIGURE 5 Evolution of monomer formation versus time.

2622
B. Rixens et al.
FIGURE 6 Hydrolysis reactions of phosphonic esters.
leading to a monoacid monomer. The diacid monomer was obtained
quantitatively by a silylation using bromotrimethyl silane followed by
methanolysis.30–32
Synthesis of Monoacid Monomer
The monoacid monomer was selectively synthesized by a methanol
hydrolysis in two steps in neutral medium. First, a dealkylation reac-
tion with Sodium iodide (at 50◦C during 5 h) led to the phosphonated
monosalt. Then an acidification reaction was realized in methanol with
1
a sulfonic resin. NMR analysis was carried out. For IEMPC1 the H
NMR spectrum showed an intensity decrease of the signal at 3.8 ppm
for the methylphosphonated groups. The integral value of this signal
(6H for the diester form) was equal to 3H, which confirmed the mono-
hydrolysis. On the 31P NMR, the singlet at 21.5 ppm was attributed
to the monoacid form. Similar results were obtained with the second
monomer IEMPC2.
Synthesis of Diacid Monomer
The diacid monomers were synthesized by silylation of phospho-
nic esters. This reaction was realized in dichloromethane by addi-
tion of bromotrimethylsilane followed by methanolysis. This reaction
1
was performed with both monomers IEMPC1 and IEMPC2. The H
NMR spectrum showed that the methylphosphononic (dimethyl phos-
phonate) (P(O)(OCH3)2) ester signal totally disappeared, proving the
diacid monomer structure. The 31P NMR spectrum showed a singlet at
20 ppm for IEMPC1 and a singlet at 26 ppm with IEMPC2.
CONCLUSION
This article reports the synthesis of two phosphonated methacry-
late monomers. The mono- and dihydrolysis were realized with both
monomers. These products were obtained by reaction between a
methacrylate bearing an isocyanate function (IEM) and two phos-
phonated alcohols with one or two carbon spacer. Unlike the usual

Phosphonated Monomers
2623
esterification and transesterication techniques, these syntheses were
quantitative and easy to achieve.
EXPERIMENTAL
1H and 31P NMR analyses were performed on a 200 MHz Bruker appa-
ratus in CDCl3, The internal reference is tetramethylsilane (TMS) for
1H NMR and orthophosphoric acid H3PO4 for 31P NMR. Protons were
irradiated for 31P NMR analyses in order to suppress the couplings
between phosphorus and hydrogen atoms. Chemical shifts are given in
ppm, and the assignations s, d, t, q, and m mean singlet doublet, triplet,
quadruplet, and multiplet, respectively.
Synthesis of Phosphonated Precursors
The dimethyl hydroxymethyl phosphonate (alcohol C1) and the
dimethyl hydroxyethyl phosphonate (alcohol C2) had been synthesized
as already described.21,22,24–28
Monomers Synthesis
Synthesis of IEMP with Phosphonated Alcohol (C1):
IEMPC1
In a two-necked, round-bottom flask (100 ml) equipped with a Dean-
Stark, 9.03 g (6.45 × 10−2 mol.) of phosphonated alcohol (C1) and 50 ml
of toluene were introduced. An azeotropic evaporation of water was
realized during half an hour (70◦C, 160 mm Hg). Then, 10 g (6.45 ×
10−2 mol.) of 2-isocyanatoethyl methacrylate (IEM) were added drop by
drop in the mixture at room temperature and under inert atmosphere
(Ar).
The reaction was monitored by infrared spectroscopy (FTIR). After
10 h at room temperature, the phosphonated monomer was obtained
with a quantitative yield.
1H NMR (CDCl3) δ (ppm): 1.5 (s, 3H, CH2 CCH3)2, 3.3 (q, 2H,
OCH2CH2NH), 3.4 (d, 6H, P(OCH3)2), 4 (t, 2H, OCH2CH2NH); 4.3 (d,
2H, CH2P(O)(OMe)2); 5.5 (s, H, CH2 C(CH3); 6 (s, H, CH2 C(CH3); 6.1
(t, 1H, CH2NH). 31P NMR (CDCl3): δ(ppm): 23 (s).
Synthesis of IEMP with Phosphonated Alcohol
(C2): IEMPC2
In a round-bottom flask, 10 g (6.45 × 10−2 mol.) of 2-isocyanatoethyl
methacrylate (IEM) and 9.93 g (6.45 × 10−2 mol.) of phosphonated

2624
B. Rixens et al.
alcohol (C2) were introduced. The reaction was carried out in bulk at
room temperature under nitrogen and was quantitative after 6 h. The
reaction rate was followed by 31P NMR spectroscopy.
1H NMR (CDCl3) δ (ppm): 1.5 (s, 3H, CH2 CCH3)2, 1.6–1.9 (m, 2H,
OCH2CH2P), 3–3.2 (m, 2H, CH2NH), 3.4 (d, 6H, P(OCH3)2), 3.8–4 (m,
4H, OCH2), 5.5 ppm (s, H, CH2 C(CH3); 6 ppm (s, H, CH2 C(CH3)),
6.1 (m, 1H, NH) 31P NMR (CDCl3) δ (ppm): 30 (s).
Hydrolysis of Phosphonated Functions of Monomers
Synthesis of the Monoacid Product
In a round-bottom flask equipped with a condenser, the phospho-
nated monomer (C1) (5 g, 1.78 × 10−2 mol.) and sodium iodide (4 g,
2.37 × 10−2 mol.) were introduced in 50 ml of acetone. The mixture was
heated at 50◦C during 14 h. Then, the solution was cooled at room tem-
perature during 6 h. The phosphonated salt was filtered and washed
twice with acetone to eliminate of iodine salts. The obtained powder
was dried under vacuum, 70% yield.
The phosphonated salt was dissolved in methanol and treated by
10 g of sulfonic resin (Amberlite IR-120) with chromatographic column.
The phosphonic monoacid monomer was obtained after evaporation of
methanol (96% yield).
1
IEMP C1. H NMR (CDCl3) δ (ppm): 1.5 (s, 3H, CH2 CCH3)2, 3.3
(q, 2H, OCH2CH2NH), 3.4 (d, 3H, P(OCH3)2), 4 (t, 2H, OCH2CH2NH);
4.3 (d, 2H, CH2P(O)(OCH3)(OH)); 5.5 (s, H, CH2 C(CH3); 6 (s, H,
CH2 C(CH3); 6.1 (t, 1H, CH2NH). 31P NMR (CDCl3) δ (ppm): 21.5 (s).
1
IEMP C2. H NMR (CD3OD) δ (ppm): 1.5 (s, 3H, CH2 CCH3)2,
1.6–1.9 (m, 2H, OCH2CH2P), 3–3.2 (m, 2H, CH2NH), 3.4 (d, 3H,
P(O)(OCH3)(OH)), 3.8–4 (m, 4H, OCH2), 5.5 (s, H, CH2 C(CH3); 6 (s,
H, CH2 C(CH3), 6.1 (m, 1H, NH), 31P NMR (CD3OD) δ (ppm): 28 (s).
Synthesis of the Diacid Product
In a two-necked, round-bottom flask (100 ml) equipped with a con-
denser and a septum, the phosphonated monomer was introduced in
25 ml of dry dichloromethane. After a 30 min argon purge, two mo-
lar equivalents of bromotrimethyl silane were added drop by drop. The
mixture was stirred for 24 h at room temperature. Then, the silylated
monomer was concentrated by evaporation of dichloromethane and dis-
solved in 25 ml of methanol. The solution was stirred for 2 h at room tem-
perature. After evaporation of methanol the phosphonated monomer
was obtained (90% yield).

Phosphonated Monomers
2625
1
IEMP C1. H NMR (CD3OD) δ (ppm): 1.5 (s, 3H, CH2 CCH3)2, 3.3 (q,
2H, OCH2CH2NH), 4 (t, 2H, OCH2CH2NH); 4.3 (d, 2H, CH2P(O)(OH)2);
5.5 ppm (s, H, CH2 C(CH3); 6 (s, H, CH2 C(CH3); 6.1 (t, 1H, CH2NH).
31P NMR (CD3OD) δ (ppm): 20 (s).
1
IEMP C2. H NMR (CD3OD) δ (ppm): 1.5 (s, 3H, CH2 CCH3)2, 1.6–
1.9 (m, 2H, OCH2CH2P), 3–3.2 (m, 2H, CH2NH), 3.8–4 (m, 4H, OCH2),
5.5 ppm (s, H, CH2 C(CH3); 6 ppm (s, H, CH2 C(CH3), 6.1 (m, 1H,
NH). 31P NMR (CD3OD) δ (ppm): 26 (s).
REFERENCES
[1] C. Brondino, B. Boutevin, J.-P. Parisi, and J. Schrynemackers, J. Appl. Polym. Sci.,
72, 611 (1999).
[2] A. Riondel, R. Pirri, and T. Jeanmaire, Eur. Pat. Appl., Ep 1201674, 9 pp. (2002).
[3] B. Youssef, L. Lecamp, W. El Khatib, C. Bunel, and B. Mortaigne, Macromol. Chem.
Phys., 204, 1842 (2003).
[4] F. Ignatious, A. Sein, and J. Smid, Polym. Prepr. (Am. Chem. Soc. Div. Polym. Chem.),
32, 170 (1991).
[5] F. Ignatious, A. Sein, I. Cabasso, and J. Smid, J. Polym. Sci., Part A: Polym. Chem.,
31, 239 (1993).
[6] S. Lin and I. Cabasso, J. Polym. Sci., Part A: Polym. Chem., 35, 889 (1997).
[7] E. P. Squiller and J. W. Rosthauser, Polym. Mater. Sci. Eng., 55, 640 (1986).
[8] E. P. Squiller and J. Rosthauser, Modern Paint Coatings, 77, 28, 35 (1987).
[9] E. P. Squiller and J. W. Rosthauser, Proceedings of the Water-Borne and Higher-
Solids Coatings Symposium, 14, 460 (1987).
[10] N. Nakabayashi, K. Kimura, and S. Takahashi, Jpn. Kokai Tokkyo Koho, Jp
63107954, 7 pp. (1988).
[11] Y. H. Kim and H. S. Park, Synlett., 3, 261 (1998).
[12] A. G. Davies and R. J. Puddephatt, J. Chem. Soc. [Section] C: Organic, 12, 1479–1483
(1968).
[13] R. B. Moffett, J. Chem. Eng. Data, 25, 176 (1980).
[14] Q. S. Yu, B. Schonenberger, and A. Brossi, Heterocycles, 26, 1271 (1987).
[15] A. Benalil, P. Roby, B. Carboni, and M. Vaultier, Synthesis, 9, 787 (1991).
[16] R. W. Hoffmann, S. Dresely, and J. W. Lanz, Chem. Ber., 121, 1501 (1988).
[17] I. Muntean, J. M. Herdan, and G. Valeanu, Rev. Roum. Chim., 33, 467 (1988).
[18] F. Bachmann, D. Lohmann, and P. Chabrecek, Eur. Pat. Appl., Ep 668294, 23 pp.
(1995).
[19] R. D. Sayakhov, A. V. Mironov, V. I. Galkin, R. A. Cherkasov, G. A. Kutyrev, and
A. N. Pudovik, Dokl. Akad. Nauk SSSR, 325, 746 [Chem.] (1992).
[20] R. D. Sayakhov, A. V. Mironov, V. I. Galkin, G. A. Kutyrev, and R. A. Cherkasov,
Zhurnal Obshchei Khimii, 63, 2476 (1993).
[21] T. Jeanmaire, Y. Hervaud, and B. Boutevin, Phosphorus, Sulfur, and Silicon, 177,
1137 (2002).
[22] T. Jeanmaire, The`se, Universite´ Montpellier II, Montpellier, France (2002).
[23] A. N. Pudovik, M. G. Zimin, and A. M. Kurguzova, Zhurnal Obshchei Khimii, 41,
1964 (1971).
[24] D. K. Owens, J. Appl. Polym. Sci., 19, 3315 (1975).

2626
B. Rixens et al.
[25] C. O. Kunz, P. C. Long, and A. N. Wright, Polym. Eng. Sci., 12, 209 (1972).
[26] K. Ishihara, Y. Iwasaki, S. Ebihara, Y. Shindo, and N. Nakabayashi, Colloids Surf.
B: Biointerfaces, 18, 325 (2000).
[27] Z. Liqun, G. S. Irwan, T. Kondo, and H. Kubota, Eur. Polym. J., 36, 1591 (2000).
[28] M. Gaboyard, The`se, Universite` Montpellier II, Montpellier, France (2001).
[29] B. Boutevin, Y. Hervaud, T. Jeanmaire, A. Boulahna, and M. Elasri, Phosphorus,
Sulfur, and Silicon, 174, 1 (2001).
[30] C. Brondino, B. Boutevin, Y. Hervaud, N. Pelaprat, and A. Manseri, J. Fluorine
Chem., 76, 193 (1996).
[31] B. Boutevin, B. Hamoui, and J. P. Parisi, J. Appl. Polym. Sci., 52, 449 (1994).
[32] R. Rabinowitz, J. Org. Chem., 28, 2975 (1963).