Note: Descriptions are shown in the official language in which they were submitted.
CA 022~0333 1998-10-1~
HydrolYsis-stable and PolYmerizable acrYlphosphonic acids
The present invention relates to polymerizable acrylphosphonic
acids which have a high degree of hydrolytic stability and are
suitable in particular for the preparation or as components of
polymers, adhesives or other materials and in particular of
5 dental materials.
Polymerizable phosphonic acids are of importance in polymer
chemistry above all as comonomers, and they allow the preparation
of organic polymers in which thermal stability, adhesive
10 properties, flammability and solubility in polar solvents are
improved. To this end, numerous monomeric phosphonic acids
having polymerizable vinyl, dienyl, allyl or styryl groups were
synthesized and polymerized. An overview of phosphonic acids is
given by Houben-Weyl, Methoden der Organischen Chemie, Volume E
15 20, (2nd part), Georg Thieme Verlag, Stuttgart-New York 1987,
page 1300 et seq. Examples of such conventional polymerizable
phosphonic acids are vinylphosphonic acid, allylbenzenephosphonic
acid, ~-aminoallylphosphonic acid, phenylethenephosphonic acid,
1,3-butadiene- or isoprenephosphonic acid, 4-
20 vinylbenzenephosphonic acid or 2-(4-vinylphenyl)-ethane
phosphonic acid.
However, phosphonic acids in which the double bond is bound to
the phosphorus atom directly or via an oxygen atom, such as
25 vinylphosphonic acid or ethylphosphonic acid monovinyl ester,
exhibit an only moderate tendency to homopolymerization.
Therefore, only homopolymers with a small molecular weight can
be obtained from them. In contrast, high-molecular-weight
polymerizates can be obtained from (meth)acrylphosphonic acids
30 or esters in which the (meth)acrylic group is not bound directly
to the phosphorus. Known (meth)acrylphosphonic acid derivatives
are e.g. the phenylphosphonic acid-mono-(methacryloyloxyethyl)-
esters of formula (a) or tert-butylphosphonic acid mono[1,3-
di(methacryloyloxy)propan-2-yl)-esters of formula (b), described
CA 022~0333 1998-10-1~
in DE-B-27 11 234. O O
O ~ C-F ~ ~ ~
(a) I (b)
C11
Moreover, acrylic acid-(2-phosphono-1,1-dimethylethylamine) is
known from DE-A-32 10 775 and methacrylic acid-(2-phosphono-1,1-
dimethylethylamine) of the formula (c) is known from DE-A-33 13
10 819 and JP 62-63314 (Chem. Abstr. 107 (1987), 41318f).
~ ~ H2- F-O~ (R = H or CH3) (c)
P~ C~3 OH
Acrylic acid-(2-phosphono-1,1-dimethylethylamine), also called
20 acrylamido-2-methylpropanephosphonic acid, is used in the form
of its homo- or copolymers as corrosion inhibitors (cf. EP-B-89
654 and US-A-4 650 591).
Finally, N-acryl-aminomethanebisphosphonic acid of the formula
25 (d) is also described in DD-A-273 846.
Il P(O(OH)2
NH-¢H (d)
P(C(OHj
All of these known (meth)acrylphosphonic acid derivatives are,
however, not stable in aqueous solution. Rather, a hydrolytic
cleavage of the (meth)acrylic group takes place which is even
catalysed by dissociated protons of the phosphonic acid group and
35 thereby accelerated.
CA 022~0333 1998-10-1
-- 3 --
However, the use of aqueous solutions is advantageous or
absolutely necessary in a whole series of applications of
polymerizable phosphonic acids. This is e.g. the case in the
preparation of low-viscosity adhesives which are free of organic
5 solvents, or in that of dental adhesives which result in an
optimum wetting of the moist dentine surface only in aqueous
form.
It is therefore the object of the invention to make available
10 polymerizable acrylphosphonic acids which are hydrolysis-stable
in aqueous solution and have good adhesion properties, can be
polymerized using conventional radical initiators and are
therefore suitable as a component of in particular adhesives,
shaped bodies, cements or composites and above all of dental
15 materials.
This object is surprisingly achieved by the hydrolysis-stable and
polymerizable acrylphosphonic acids according to Claims 1 and 2.
20 The subject of the present invention is also the process for the
preparation of the acrylphosphonic acids according to Claim 3,
the use thereof according to Claims 4 to 6, the dental material
according to Claims 7 and 8, and polymers and copolymers of the
acrylphosphonic acids according to Claim 9.
The acrylphosphonic acids according to the invention are
compounds of the following general formula (I), stereoisomers
thereof and mixtures of such stereoisomers
_ ~ _
~/\C--OR
Y O
X ¦ R- (I)
R3
C~=P-OH
1H - n
CA 022~0333 1998-10-1
-- 4
where Rl, R2, R3, X, Y and n, unless stated otherwise,
independently of one another have the following meanings:
Rl = hydrogen, Cl to C10 alkyl or C6 to C~O aryl,
R2 = hydrogen, fluorine, Cl to C5 alkyl or phenyl,
R3 = Cl to C8 alkylene, phenylene or is absent,
Y = oxygen, sulphur, C~ to C8 alkylene or is absent,
n = 1 or 2,
and with the proviso that
(a) for n = 1
X = hydrogen, fluorine, C~ to C5 alkyl or C6 to
C~2 aryl,
and
(b) for n = 2
X = C~ to C10 alkylene, C6 to C~O arylene, C7 to
C20 arylenalkylene or is absent.
20 The individual alkyl and alkylene radicals can be straight-chain,
branched or cyclic. Moreover, the individual alkyl, aryl,
alkylene, arylene, phenyl, phenylene and arylenalkylene radicals
can bear one or more substituents, such as Cl, Br, CH3, C2H5,
CH30, OH, COOH, CN or NO2.
There also exist for the above-mentioned variables of the formula
(I) preferred definitions which, unless otherwise stated, can be
chosen independently of one another and are as follows:
30 Rl = hydrogen, Cl to C5 alkyl or phenyl,
R2 = hydrogen, fluorine or C~ to C3 alkyl,
R3 = C~ to C3 alkylene, phenylene or is absent,
Y = oxygen, C~ to C3 alkylene or is absent,
n = 1 or 2,
CA 022~0333 1998-10-1
and with the proviso that
(a) for n = 1
X = hydrogen, fluorine, Cl to C3 alkyl or phenyl,
and
(b) for n = 2
X = C~ to C6 alkylene, phenylene or is absent.
Preferred compounds are therefore those in which at least one of
10 the variables of the formula (I) has the above-described
preferred definition, the formula (I) including all stereoisomers
made possible by the mentioned substituents and their mixtures,
such as racemates.
15 The acrylphosphonic acids according to the invention of the
formula (I) can be prepared by reaction of a-halomethylacrylic
acid esters of the formula (II) with protected mono- or
difunctional phosphonic acid esters of the formula (III) and
cleavage of the protective groups. In the formulae (II) and (III)
20 U is halogen, SG is protective group and the other variables are
as defined above for formula (I). This reaction can be
illustrated by the following general reaction equation which is
followed by a concrete example.
~C--ORt
'' .I 11
X ~ ~ I -n UH I -
3 I r, ~ C_o.~l ~ X
I ~ O (+ cleavage ~
OSG n C=P-O~ n
C! i
(III) (II) (I)
CA 022~0333 1998-10-1
-- 6 --
Concrete examPle:
C Hs-O r 3r C ~ I ~ ~ cH_p,OC2Hs
+HsC20 0 0 ~C2Hs
H H
-2 HBr (+ cleavage
~ of SG)
~ ~CH--P(OH)~
C :i, C H2
I~=o c=r
CC2Hc CC~Hc
The reaction can be conducted by using the methods known from
20 organic chemistry for forming C-C, C-O or C-S bonds (cf. C.
Weygand, G. Hilgetag, Organisch-chemische Experimentierkunst,
Johann Ambrosius Bart Verlag, Leipzig 1970, pages 963 et seq.,
362 et seq. and 657 et seq.).
25 Used as protective groups (SG) are customary protective groups
for phosphoric acid groups, such as ester groups, in particular
SG is ethyl. After the reaction has taken place, these are split
off according to conventional processes, in order to liberate the
acrylphosphonic acids of the formula (I). The hydrolytic
30 cleavage of the protective groups SG is effected in particular
by silylation with trialkylsilanes, e.g. trimethylsilyl chloride
mixed with sodium iodide or bromide, and subsequent reaction with
alcohols or water (cf. S. Freeman, J. Chem. Soc., Perkin Trans,
2 (1991) 263).
CA 02250333 1998-10-15
The ~-halomethylacrylic acid esters (II) used as starting
materials can be obtained e.g. by reaction of the corresponding
acrylic acid esters with formaldehyde in the presence of 1,4-
diazabicyclo[2,2,2]octane (DABCO) and subsequent halogenation
5 with inorganic acid chlorides, such as SOClz, PCl3 or PBr3 (cf.
L.J. Mathias et al., Macromolecules 20 (1987) 2039, 2326, J.
Polym. Sci.: Part A: Polym. Chem. 32 tl994) 2937), and this
reaction is illustrated by the following equation and a concrete
example:
1R--o H~ 1R--O -rOH 1R--O U
O~ o~ - P(OH)3
(U = Br or Cl) (II)
Concrete example:
C2Hs-O +H'C O C2H5-O OH p~3 C2Hs-O r Br
O ~ H (CABCO) ~ - P(OH~
Suitable protected mono- or difunctional phosphonic acid esters
(III) can be obtained by different methods. A particularly
suitable method proceeds via the Michaelis-Arbusow reaction for
the preparation of alkylphosphonic acid esters (cf. G.M.
25 Kosolapoff, Org. Reactions 6 (1951) 273). In this process,
trialkyl phosphites, e.g. triethyl phosphite, and haloalkanes are
reacted in accordance with the equations below, in which the Y-H
group must also be protected where necessary.
H H
y
~P--OC2Hs t R2 Br C2Hs ~3
C2HsO Br O=P-OS~
- -n OSG ~n
(SG =C~H~) (III)
CA 022~0333 1998-10-1
Concrete examPle:
C2HsO OH
P--OC2 H; C H2
C2H;O - Br-C2Hs ¢H2
B r--C H2--C H2--OH O=P--OC2 Hs
OC2 H5
Arylphosphonic acids can be obtained e.g. by Friedel-Crafts
10 reaction of aromatic hydrocarbons with phosphorus trichloride in
the presence of aluminium trichloride, chlorination of the formed
dichlorophosphine to tetrachlorophosphine and subsequent
hydrolysis to the phosphonic acid (cf. G.M. Kosolapoff, Org.
Reactions 6 (1951) 273).
Furthermore, protected hydroxyalkylphosphonic acid esters (Y-H
= OH) where R3 = absent can be prepared by adding dialkyl
phosphites with base catalysis to mono- or difunctional aldehydes
or ketones analogously to the process according to F. Texier-
20 Boullet, A. Foucaud, Synthesis, 1982, 916. This type of reactionand a concrete example thereof are shown by the following
reaction equations:
H
O
C2H5O~"O O -Br-C2Hs
C2HaO' + X ll ~ ' C=P-OSG
(SG=C2Hc) -n
Concrete examPle:
C2HsO'P'OH ~~ ~ O-p-oc2Hs
OC2H;
CA 02250333 1998-10-15
Examples of the acrylphosphonic acids according to the in~ention
of formula (I) are inter alia:
HO O ~ - O O ~
~ e (~H?2 ~ o(OH)z
~ I (OH)2 ~ ~/\o(~H)2
r~~ --e(OHj2 ~ ~ --e(OH)~
O O ~ HO r O
o~ o o~ ~
HO O~ rO O~
o~ e(OH)~~ o(OH)2
~/ ~
HO rO~ ~O rO~
0 ~ P(OH)2 ~ lo(OH)2
0~ 0
HO~ Pl (oH)2 r ~ lo(OH)2
r /e~~H)2 ~ / IP! ~OH)2
o~\ O ~ F O
CA 022~0333 1998-10-15
- 1~ - F
HoO~ ~1 (OH)2 ~--~~ ll (OH)2
o~ P(oH)2 HO~ I o(OH)2
~ ~ F(OH)2 ~~ F o(OH)2
(HO~2P--CH~--CH--F(OH~2 (HO)2P--CH- <~--CH--P~OH)2
CH, CH,~ CH- CH2~=
Cl=O O=C C=O O=C
OC2H~ OC2H~ OH OH
~HO)2P---ICH--~CH,)~ Cl I--P(OH)2 (HO)2P--CH--(CH2)--CH--P(OH)2
~0 0 0 0
=CH2 CH2~=~ CH2 CH2~=
C=O O=C C=O O=C
OC2H~ OC2H5 Otl OH
(HO)CP--Clt{;H--P(oH)2 (HO)2P--CH~H--P(OH32
'~ 1~ 1~ ~
C H2 C H2~= C H2 C H2~=
!CO OC ICO O!C
OC2H~ OC2Hs OH OH
. . ,
,,, . .. ,.. , ~
CA 022~0333 1998-10-1~
Due to the presence of polymerizable groups the acrylphosphonic
acids according to the invention are suitable as starting
materials for the preparation of polymers and copolymers. They
can be homopolymerized using the known methods of radical
5 polymerization or copolymerized e.g. with suitable comonomers.
In order to carry out the polymerization, the known radical
initiators (cf. Encyclopedia of Polymer Science and Engineering,
Vol. 13, Wiley-Interscience Publisher, New York 1988, 754 et
10 seq.) can be used. Suitable in particular are azo compounds,
such as azobis(isobutyronitrile) (AIBN) or azobis(4-cyanovaleric
acid), or peroxides, such as dibenzoyl peroxide, dilauroyl
peroxide, tert-butyl peroctoate, tert-butyl perbenzoate or di-
(tert-butyl)peroxide.
Benzpinacol and 2,2'-dialkylbenzpinacols are also suitable as
initiators for the hot curing.
Furthermore, photoinitiators (cf J.P. Fouassier, J.F. Rabek
20 (publisher), Radiation Curing in Polymer Science and Technology,
Vol. II, Elsevier Applied Science, London and New York 1993) can
also be used for polymerization with W light or visible-
wavelength light, such as benzoin ethers, dialkylbenzil ketals,
dialkoxyacetophenones, acyl phosphine oxides, ~-diketones, such
25 as 9,10-phenanthrenequinone, diacetyl, furil, anisil, 4,4'-
dichlorobenzil and 4,4'-dialkoxybenzil, and camphor quinone.
The acrylphosphonic acids can be used in particular as a
components of adhesives, of cements, of composites and shaped
30 bodies and preferably of dental materials. It is possible that
they are present in at least partially polymerized form. Other
components with which the acrylphosphonic acids can be combined
are mentioned below.
35 The acrylphosphonic acids according to the invention can be
polymerized alone or mixed with conventional radically
CA 022~0333 1998-10-1
-- 12 --
polymerizable comonomers, in particular with difunctional
crosslinking monomers. Suitable for the preparation of adhesives
or dental materials are above all crosslinking bi- or
polyfunctional acrylates or methacrylates, such as bisphenol-A-
5 di(meth)acrylate, the addition product, called bis-GMA, of
methacrylic acid and bisphenol-A-diglycidyl ether; the addition
product, called UDMA, of hydroxyethyl methacrylate and 2,2,4-
trimethylhexamethylene diisocyanate; di-, tri- or tetraethylene
glycol di(meth)acrylate; decanediol di(meth)acrylate;
10 trimethylolpropane tri(meth)acrylate and pentaerythritol
tetra(meth)acrylate. The compounds butanediol di(meth)acrylate,
1,10-decanediol di(meth)acrylate and 1,12-dodecanediol
di(meth)acrylate, which can be obtained by esterification of
(meth)acrylic acid with the corresponding diols, are also
15 suitable.
Moreover, the acrylphosphonic acids according to the invention
or mixtures thereof with other radically polymerizable comonomers
can be filled with organic or inorganic particles or fibres in
20 order to improve the mechanical properties. Preferred inorganic
particulate fillers are amorphous spherical materials based on
mixed oxides of SiOz, ZrO2 and/or TiO2, microfine fillers such as
pyrogenic silica or precipitated silica, and macro- or mini-
fillers, such as quartz powder, glass ceramic powder or glass
25 powder having an average particle size of 0.01 to 5 ~m. Finally,
X-ray-opaque fillers, such as ytterbium trifluoride, or glass
fibres, polyamide fibres or carbon fibres can also be used.
If necessary, further components can be added to the
30 acrylphosphonic acids, above all solvents, such as water, ethyl
acetate, acetone, ethanol or mixtures thereof, and stabilizers,
W absorbers, dyes, pigments or lubricants.
The acrylphosphonic acids according to the invention are suitable
35 in particular as a component of dental materials, such as fixing
cements and filling composites and above all dental adhesives.
CA 022~0333 1998-10-1~
Such materials are characterized by very good adhesion to
different substrates, such as tooth dentine and metallic
substrates, which can be attributed to the acrylphosphonic acids
used. It is assumed that the acrylphosphonic acids form ionic
5 and/or complex compounds with the calcium ions of the tooth
dentine or with the metal ions of metallic substrates. These
result in a greater adhesion than would be possible on the basis
of simple dipole-dipole or van der Waals' interaction.
10 The surprisingly high hydrolytic stability of the acrylphosphonic
acids also endows the materials according to the invention with
a very good hydrolytic stability. This is true both for the
unpolymerized and the polymerized material. A high hydrolytic
stability is naturally of particular importance to those
15 materials which are permanently exposed to aqueous media, as is
precisely the case with dental materials which are planned to
reside in the oral cavity for a relatively long time.
Preferred dental materials according to the invention contain the
20 following components (a), (b), (c), (d) and/or (e):
(a) 1 to 99 wt.%, preferably 10 to 80 wt.% and particularly
preferably 20 to 70 wt.% acrylphosphonic acids according to
the invention,
(b) 0.01 to 5 wt.% and preferably 0.1 to 2.0 wt.% radical
initiator,
(c) 0 to 80 wt.%, preferably 0 to 60 wt.% and particularly
30preferably 0 to 50 wt.% radically polymerizable comonomers,
(d) 0 to 95 wt.%, preferably 0 to 80 wt.% and particularly
preferably 0 to 70 wt.% solvent,
CA 022~0333 l998- lO- l~
-- 14 --
(e) 0 to 90 wt.%, particularly preferably, depending on the
application, 0 to 20 wt.% (adhesive), 20 to 60 wt.%
(cement) and 60 to 85 wt.% (filling composite) filler.
5 The invention is explained in more detail below with reference
to examples.
ExamPles
10 Example 1
1st staqe: 2- r 3-(diethoxyphosphoryl)-2-oxa-propyll-acrylic
acid ethyl ester (1)
7.45 g (50 mmol) a-chloromethylacrylic acid ethyl ester were
15 added at room temperature with stirring to a solution of 8.4 g
(50 mmol) hydroxymethylphosphonic acid diethyl ester, which is
- easily obtainable by reacting diethyl phosphite with
paraformaldehyde, 5.05 g (50 mmol) triethylamine (TEA) and 0.01
g phenothiazine (stabilizer) in 40 ml absolute tetrahydrofuran
20 (THF). After 30 minutes' stirring at room temperature, the
mixture was heated under reflux for 16 hours. After cooling to
room temperature, the formed precipitate of triethylammonium
chloride was filtered off. The filtrate was diluted with 150 ml
water, set to a pH value of ca. 5 to 7 with 2N hydrochloric acid
25 and extracted repeatedly with diethyl ether. After drying over
anhydrous NazSO4, the extract was concentrated in a rotary
evaporator, dried under a medium vacuum and finally distilled by
fractionation. 10.8 g [b.p.: 120-125 C (0.007 mbar)] of a
colourless liquid were obtained (77 % yield).
Elemental analysis:
CllH2lO6P Calc.: C 47.14 H 7.55
(280.26) Found: C 47.58 H 7.87
CA 022~0333 1998-10-1
- 15 -
IR (KBr, cm ): 780 (w), 818 (w), 877 (w), 967 (s), 1029 (s,sh),
1112 (s), 1176 (m), 1261 (s), 1306 (m), 1392 (m,sh), 1446 (w),
1719 (s), 2908 (w) and 2984 (m).
5 lH-NMR (300 MHz, CDCl~, ppm): 1.29-1.42 (m, 9H, CH3), 3.80 (d,
2H, CH2-P), 4.10-4.26 (m, 6H, CH2-CH3), 4.34 (s, 2H,CH2-C=CH2),
5.90 and 6.33 (s, 2xlH, C=CH2).
C-NMR (75 MHz, CDCl~, ppm): 14.20 and 16.47 (CH31), 60.78,
10 62.50, 63.68, 65.89 and 71.38 (all CH2t), 126.66 (CH2=Ct), 136.64
(CH2=C(-)) and 165.51 (C=O(-)).
3lP-NMR (121.5 MHz, CDCll, Ppm): 43Ø
~5 2nd staqe: 2- r 3-(dihYdroxyPhosPhorYl)-oxa-propyll-acrylic
acid ethyl ester (2)
O ~ O ~ P(OH)2 (2)
16.8 g (110 mmol) trimethylsilyl bromide were added dropwise to
a solution of 14.0 g (50 mmol) of compound (1) and 0.01 g
hydroquinone monomethyl ether (MEHQ, stabilizer) in 30 ml
25 absolute methylene chloride, and the mixture was stirred for 90
minutes under reflux. The mixture was then concentrated in a
rotary evaporator, and the obtained residue was stirred for 2
hours after being taken up in 50 ml methanol. After treating the
slightly reddish solution with activated charcoal, the solution
30 was concentrated in vacuo and then dried under a medium vacuum
until the weight was constant. 9.1 g (81 % yield) of a viscous
oil remained which had a purity of 98 % determined by means of
HPLC.
CA 022~0333 1998-10-1
- 16 -
Elemental analYsis:
C7H13O6P Calc.: C 37.51 H 5.85
(224.15) Found: C 37.26 H 6.87
IR (KBr, cm ): 684 (w), 778 (w), 820 (m), 861 (m), 970 (s),
1020 (s), 1112 (s), 1182 (s,sh), 1309 (s,sh), 1405 (m,sh), 1466
(m,sh), 1632 (m), 1713 (s), 2324 (b) and 2600-3500 (b).
10 H-NMR (300 MHz, acetone-d~, ppm): 0.32 (ca. 1 % silyl
compound), 1.28 (t, 3H, CH3), 3.86 (d, 2H, PCH2), 4.20 (q, 2H,
CH2CH3), 4.33 (s, 2H, CH2C=C), 5.96 and 6.30 (s, 2xlH, C=CH2) and
11.38 (s, b, 2H, OH).
C-NMR (75 MHz, acetone-d~, ppm): 14.2 (CH3l), 61.25 (CH2CH3t),
64.75 and 66.9 (d, CH2Pt), 71.35 (CH2C=Ct), 126.15 (C=CH2t), 137.6
(C=CH2(-)) and 165.75 (C=O).
P-NMR (121.5 MHz, acetone-d~, Ppm): 47Ø
Example 2
1st staqe: 2- r 4-dimethoxYPhosphoryl)-2-oxa-butyll-acrylic
acid ethyl ester (3)
7.45 g (50 mmol) ~-chloromethylacrylic acid ethyl ester were
added at room temperature with stirring to a solution of 7.7 g
(50 mmol) hydroxyethylphosphonic acid dimethyl ester, 5.05 g (50
mmol) TEA and 0.01 g phenothiazine in 40 ml absolute THF. The
30 process was then continued analogously to Example 1 (lst stage).
The fractional distillation produced 2.1 g [b.p. 115-120~C (0.005
mbar)] of a colourless liquid (16 % yield).
CA 022~0333 1998-10-1
- 17 -
Elemental analysis:
CloHl9O6p Calc.: C 45.11 H 7.19
(266.23) Found: C 45.45 H 7.26
IR (KBr, cm ): 645 (w), 732 (m), 820 (s), 954 (m), 1032 (s,b),
1105 (s), 1179 (s), 1267 (s), 1306 (s), 1375 (m,sh), 1464 (m,sh),
1640 (m), 1715 (s), 2234 (w), 2956 (m,sh) and 3472 (w,b).
10 H-NMR (300 MHz, CDCl~, ppm): 1.31 (t, 3H, CH3CH2), 2.10-2.21 (m,
2H, CH2P), 3.71-3.83 (m, 8H, 2xCH30 + CH7CH70), 4.18-4.28 (m, 4H,
CHlCH70 + CH2C=), 5.89 and 6.29 (s, 2xlH, C=CH2).
C-NMR (75 MHz, CDCll, ppm): 14.2 (CH3CH21), 24.0 and 27.0
15 (CH2Pt), 52.3 (CH30), 60.95 (CH3CH2t), 64.6 (CH7CH70t), 69.0
(OCH2C=Ct), 126.0 (C=CH7t), 137.4 (C=5~(-)) and 165.6 (C=O(-)).
P-NMR (121.5 MHz, CDCl~, pPm): 62Ø
~0 2nd staqe: 2-r4-dihydroxyphosphorYl)-2-oxa-butyll-acrylic
acid ethyl ester (4)
r~~ ~~--/\P (OH)2
O ~ O (4)
Analogously to Example 1 (2nd stage), 7.7 g (50 mmol)
trimethylsilyl bromide were added dropwise to a solution of 6.1
g (23 mmol) of compound (3) and 0.01 g MEHQ in 20 ml absolute
30 methylene chloride. The mixture was stirred for a further 90
minutes under reflux, then concentrated, and the residue was
reacted with 30 ml methanol and treated in accordance with
Example 1 (2nd stage). After drying under a medium vacuum until
the weight was constant, 4.3 g (79 % yield) of a viscous oil was
35 obtained as product.
CA 022~0333 1998-10-1
- 18 -
Elemental analysis:
C8Hl5O6P Calc.: C 40.34 H 6.35
(238.18) Found: C 40.86 H 6.52
IR (KBr, cm ): 718 (w), 820 (w), 1024 (s,sh), 1103 (s), 1178
(s,sh), 1273 (m,sh), 1307 (m), 1376 (m,sh), 1466 (w,sh), 1637
(m), 1717 (s), 2323 (b) and 2800-3300 (m,b).
10 H-NMR (300 MHz, acetone-d~, PPm): 1.28 (t, 3H, CH3), 2.07-2.24
(m, 2H, CHzP), 3.72-3.84 (m, 2H, CH7CH70), 4.15-4.25 (m, 4H,
CH~CH~O + CHzC=C), 5.93 and 6.25 (s, 2xlH, CH2=) and 9.80 (s, 2H,
OH).
C-NMR (75 MHz, acetone-d~, PPm): 13.0 (CH3), 27.8 and 30.3 (d,
CH2P), 61.4 (CH7CH3), 65.58 (CH7CH70), 71.6 (CHzC=CHz), 125.7
(CH2C=CH2), 138.5 (CHzC=CH2) and 166.1 (C=O).
P-NMR (121.5 MHz, CDCl~, ppm): 60Ø
Example 3
1st staqe: 1,4-bis r l-(diethoxyphosphoryl)-l-hydroxymethyll-
benzene (5)
1.1 g (0.01 mol) DABCO were added at ca. 15 C with stirring to
a solution of 13.4 g (0.1 mol) terephthalic aldehyde and 29.0 g
(0.2 mol) diethyl phosphite in 50 ml absolute acetonitrile.
After further stirring over night, the formed precipitate was
30 removed by suction, washed in each case with some acetonitrile
and petroleum ether and dried until the weight was constant.
30.7 g (75 % yield) of a white solid (m.p.: 195-200~C) were
obtained.
CA 022~0333 1998-10-1
-- 19 --
Elemental analysis:
Cl6H28O8p2 Calc.: C 46.83 H 6.68
(410.34) Found: C 46.79 H 6.43
IR (KBr, cm ): 445 (w), 494 (w), 575 (s), 658 (w), 758 (m), 791
(w), 831 (w), 861 (w), 975 (s), 1022 (s), 1056 (s), 1205 (s),
1230 (s), 1392 (m), 1445 (w), 1478 (w), 1509 (w), 1702 (w), 2911
(w), 2988 (m) and 3263 (s,b).
H-NMR (300 MHz, DMSO-d~, ppm): 1.12-1.18 (m, 12H, CH3), 3.82-
3.98 (m, 8H, CH2), 4.92 (d, 2H, CH-P), 6.20 (s, 2H, OH, H/D
exchange) and 7.38 (s, 4H, CH-arom.).
15 l3C NMR (100 MHz, DMSO-d~, Ppm): 16.13 and 16.23 (s, CH3), 61.68
and 62.08 (s, CH2), 68.31 and 69.93 (d, CH-P), 126.68 (s, CH-
arom.) and 137.54 (s, quart. arom. C).
P-NMR (162 MHz, DMSO-d~, ppm): 21.9.
2nd staqe: 1,4-bisrl-~diethoxyPhosphoryl)-l-r(2-methylen-3-
yl-ProPanoic acid ethYl ester)-oxylmethyll-
benzene t6)
25 8.9 g (60 mmol) a-chloromethylacrylic acid ethyl ester were added
at room temperature and with stirring to a solution of 12.3 g
(0.03 mol) of compound (5), 6.05 g (60 mmol) TEA and 0.02 g
phenothiazine in 100 ml absolute THF. After 30 minutes' stirring
at room temperature, the mixture was heated under reflux for 16
30 hours. After cooling to room temperature, the formed precipitate
was filtered off, washed once witk diethyl ether and twice with
water. After drying of the residue at 60~C under a medium
vacuum, 9.7 g (51 % yield) of a colourless resin were obtained.
CA 022~0333 1998-10-1
-- 20 --
Elemental analysis:
C2sH44~l2P2 Calc-: C 52.98 H 6.99
(634.60) Found: C 52.98 H 7.08
IR (KBr, cm ): 580 (s), 751 (m), 795 (m), 859 (w), 967 (s),
1028 (s), 1055 ts), 1095 (s), 1177 (s), 1257 (s), 1308 (s,sh),
1391 (s,sh), 1445 (m,sh), 1508 (w), 1636 (m), 1716 (s), 2930
(m,sh) and 2982 (s).
lN-NMR (400 MHz, acetone-d~, ppm~: 1.10-1.22 (m, 18H, CH3), 3.95-
4.01 (m, 8H, POCH2CH3), 4.10-4.16 (m, 8H, COCH2), 4.95 (d, 2H,
CH), 5.97 and 6.27 (s, 2x2H, CH2=) and 7.43 (s, 4H, CH-arom.).
15 13C NMR (100 MHz, acetone-d,~, ppm): 14.16 (CH3-methacrylate),
16.37 (CH3-phosphonate) 60.73 (OCH2CH3-methacrylate), 62.9 and
63.2 (d, OCH2CH3-phosphonate), 68.70 and 68.83 (d, CH-P), 126.82
and 128.54 (CH2= and CH-arom.), 134.97 and 136.75 (CH2=C and C-
arom.) and 165.37 (C=O).
P-NMR (121.5 MHz, DMSO-d~, PPm): 18.6.
3rd staqe: 1,4-bis r 1- ( dihydroxyphosphoryl)-1- r ( 2-methYlen-
3-yl-ProPanoic acid ethyl ester)oxYlmethvll-
benzene (7)
(HO~P--CH~CH--P(OH)2
CH2 CH2=
C=O O=C
OC2H; OC~Hs
8.6 g (56 mmol) trimethylsilyl bromide were added dropwise to a
35 solution of 7.8 g (12.3 mmol) of compound (6) and 0.01 g MEHQ in
20 ml absolute methylene chloride, and the mixture obtained was
CA 022~0333 1998-10-1
-- 21 --
stirred under reflux for 75 minutes. The mixture was then
concentrated in a rotary evaporator. After 20 ml methanol had
been added to the residue, it was stirred over night and
concentrated again in vacuo. The formed light-yellow powder was
5 taken up in 100 ml of a saturated NaHCO3 solution and washed
twice with in each case 50 ml methylene chloride. The solution
was then stirred up with activated charcoal and filtered. The
filtrate was set to pH = 1 with concentrated hydrochloric acid,
treated with 2 g NaCl and 50 ml water and then shaken out three
10 times with in each case 150 ml methylene chloride. The combined
extracts were dried over Na2SO4 and concentrated until dry in a
rotary evaporator. The residue was dried under a medium vacuum
until the weight was constant. 4.3 g (66 96 yield) of a weakly
yellowish crystalline product remained.
Elemental analysis:
C20H28O~2p2 Calc.: C 45.99 H 5.45
(522.39) Found: C 44.96 H 4.93
IR (KBr, cm ):412 (m), 569 (s), 646 (w), 815 (m), 941 (s),
1035 (s), 1093(s), 1176 (s), 1285 (sh), 1320 (sh), 1390 (sh),
1406 (m), 1460 (w), 1509 (w), 1636 (m), 1717 (s), 2987 (s) and
3440 (s,b)-
H-NMR (300 MHz, DMSO-d~/CDCl~, ppm): 1.17 (t, 6H, CH3), 4.12-
4.33 (m, 8H, CH2), 4.50-4.55 (d, 2H, CH), 6.08 and 6.27 (s, 2xlH,
=CH2), 7.36 (s, 4H, CH-arom.) and 9-10 (4H, b, OH).
C-NMR ~100 MHz, DMSO-d~/CDCl~, ppm): 14.01 (CH3), 60.37
(OCH2CH3), 68.10 and 68.23 (d, CH-P), 125.87 and 127.49 (CH2= and
CH-arom.), 135.64 and 136.85 (CH2--C and C-arom.) and 165.34
(C=O) .
35 lP-NMR (121.5 MHz, DMSO-d~, ppm): 15.1.
.._
CA 022~0333 1998-10-1
Example 4
1st staqe: r (dimethoxYPhosPhorYl ) -r ( 2-methylen-3-yl-
propanoic acid ethyl ester)oxyl-methyllbenzene
(8!
14.9 g (0.1 mol) ~-chloromethylacrylic acid ethyl ester were
added at room temperature with stirring to a solution of 21.6 g
(0.1 mol) [(dimethoxyphosphoryl)-1-hydroxymethyl]benzene, which
10 can be obtained by reacting dimethyl phosphite with benzaldehyde
(F. Texier-Boullet, A. Foucaud, Synthesis 1982, 916), 10.1 g (0.1
mol) TEA and 0.02 g phenothiazine in 200 ml absolute THF. After
30 minutes' stirring at room temperature, the mixture was heated
for 16 hours under reflux. After cooling to room temperature,
15 the formed precipitate was filtered off, and this was washed once
with diethyl ether. The washing ether and the filtrate were
diluted with 400 ml water, and the mixture obtained was extracted
three times with in each case 100 ml ether. The combined organic
extracts were washed with 100 ml saturated NaCl solution, dried
20 over Na2SO4 and concentrated in a rotary evaporator. The
remaining oily residue was then destilled under a high vacuum.
15.9 g (49 % yield) of a colourless liquid [b.p.: 153-155~C (10-5
mbar)] were obtained.
25 Elemental analysis:
Cl5H2lO6P Calc.: C 54.88 H 6.45
(328.30) Found: C 54.10 H 6.24
30 IR (KBr, cm ): 465 (s,b), 701 (m), 771 (w), 832 (m), 1031
(s,sh), 1095 (s), 1181 (s), 1262 (s), 1309 (m), 1401 (w), 1453
(m), 1637 (w), 1718 (s), 2854 (w) and 2956 (m).
N-NMR (300 MHz, CDCl~, ppm): 1.29 (t, 3H, CH3CH2), 3.65-3.73
35 (dd, 6H, POCH3), 4.14-4.33 (m, 4H, CHz), 4.78 (d, lH, CH), 5.97
and 6.34 (s, 2xlH, CH2=) and 7.34-7.47 (m, 5H, CH-arom.).
CA 022~0333 1998-10-1
- 23 -
C-NMR (100 MHz, CDCl~, ppm): 14.45 (s, CH3-methacrylatet); 54.17
(d, CH3-OPt); 61.07 (OCH2CH3-methacrylatel); 69.88 (s, OCH2C=CH21);
77.34 and 79.31 (d, CH-Pt); 126.87 (s, CH2=l); 128.32 and 128.86
(s, CH-arom.t); 134.97 and 136.75 (CH2=C and C-arom.(-)); 165.37
5 (C=O(-))
P-NMR (121.5 MHz, CDCl~, ppm): 21.3 (s).
2nd staqe: 1-(dihYdroxYPhosPhoryl)-l- r ( 2-methylen-3-yl-
propionic acid ethyl ester)-oxylmethyll-benzene
(9!
~ ~,
CH (9)
=<
C=O
~C2Ha
20 17.2 g (0.1 mol) trimethylsilyl bromide were added dropwise to
a solution of 14.4 g (44 mmol) of compound (8) and 0.01 g MEHQ
in 40 ml absolute methylene chloride, and the mixture obtained
was stirred under reflux for 75 minutes. The mixture was then
concentrated in a rotary evaporator, and the residue was reacted
25 with 40 ml methanol. The mixture was stirred for 4 hours and
concentrated in vacuo. The formed resin was taken up in 200 ml
of a saturated NaHCO3 solution and washed twice with 100 ml
methylene chloride. The solution was stirred up with activated
charcoal and filtered. The filtrate was then set to pH = 1 with
30 concentrated hydrochloric acid, treated with 4 g NaCl and 50 ml
water and then shaken out three times with in each case 100 ml
methylene chloride. The combined extracts were dried over Na2SO4
and concentrated until dry in a rotary evaporator. The residue
was dried under a medium vacuum until the weight was constant.
35 10.0 g (76 % yield) of a sticky crystalline product were
obtained.
CA 022~0333 1998-10-1~
.
- 24 -
Elemental analysis:
Cl3Hl706P Calc.: C 52.00 H 5.71
(300.25) Found: C 50.47 H 5.58
IR (KBr, cm ): 698 (s), 739 (w), 805 (w), 819 (w), 970 (s),
1026 (s,sh), 1094 (s,sh), 1178 (s,sh), 1280 (s,sh), 1320 (m),
1340 (m), 1402 (m,sh), 1453 (m,sh), 1490 (m), 1643 (m), 1713 (s),
2321 (m), 2910 (m), 2949 (m) and 2982 (m).
H-NMR (300 MHz, CDCl~, ppm): 1.22 (t, 3H, CH3), 4.06-4.17 (m,
4H, CH2), 4.50 (d, 2H, CH-P), 5.89 and 6.19 (s, 2xlH, CH2=),
7.18-7.33 (m, 5H, CH-arom.) and 10.79 (s, 2H, OH, H/D exch.).
C-NMR ~100 MHz, CDCl1, ppm): 14.08 (CH3); 60.86 (OCH2CH3); 68.49
(CH2OCH); 77.20 and 78.86 (d, CH-P); 127.49-128.25, 135.21,
136.15 (all C-arom. + CH2=C) and 166.08 (C=O).
P-NMR (121.5 MHz, CDCll, ppm): 20.1.
Example 5
Radical homopolYmerization of acrYlphosphonic acid (7)
25 2.61 g (5.0 mmol) of the acrylphosphonic acid (7) used as monomer
and 2.5 mol% azobis(isobutyronitrile), relative to the monomer,
were dissolved in 9.0 ml ethanol in a Schlenk vessel. The
monomer solution was degassed by being repeatedly frozen under
argon and defrosted under a medium vacuum and then polymerized
30 at 65~C under argon. On account of the difunctional monomer
structure, crosslinked and therefore insoluble polymeric
acrylphosphonic acid (7) was already deposited after 2 minutes.
The monomer conversion was 47.7 % after 1 hour. The formed
polymer was insoluble.
CA 022~0333 1998-10-1
- 25 -
Example 6
~mi n~tion of the hydrolYtic stabilitY of the monomeric
acrylphosphonic acids
20 wt.% solutions in EtOD/H2O (1 : 1 parts by volume) were
prepared from each of the monomeric acrylphosphonic acids (2) and
(7) according to the invention and from monomeric 2-
(methacryloyloxy)ethylphosphonic acid (10) as a comparative
10 example and were stored at 25 and 37 C. To determine the
hydrolytic stability, an H-NMR spectrum was recorded after
various times and was analysed for the formation of possible
cleavage products.
15 It was shown that no hydrolytic cleavage of the polymerizable
group had taken place in the case of the acrylphosphonic acids
(2) and (7) according to the invention even after 3 months,
whereas in the case of the conventional acrylphosphonic acid (10)
the cleavage of the ethylphosphonic acid group began after just
20 a few hours at 25 C and was detectable by the presence of 2-
hydroxyethylphosphonic acid as a cleavage product. This suggests
a hydrolytic cleavage according to the following formula.
O O
25~ O,~_,P OH Monomer(lo)
~ OH (Comparative Example)
Hydrolytic cleavage
Example 7
~mi n~tion of the adhesion to metal of the acrylphosphonic
acids
Wiron 88 (Thyssen-Bego), an Ni-Cr-Mo dental alloy customary in
35 the trade, was sandblasted and cleaned with superheated steam.
A primer consisting of 10.0 wt.% of the acrylphosphonic acid (7),
.
CA 022~0333 1998-10-1~
45.0 wt.% water, 44.7 wt.% ethanol and 0.3 wt.% camphor quinone
was then brushed on in a thin layer, and Variolink (Vivadent
Ets., Liechtenstein), a commercial light-curing adhesive for
filling composites, was applied to it and exposed to light. A
5 dividible Teflon mould (d=4mm, h=6mm) was then fixed with a
securing means to the metal surface, and a light-curing filling
composite, namely Tetric (Vivadent Ets., Liechtenstein) was
polymerized in layers onto the metal surface in a volume
predetermined by the Teflon mould and on an adhesion surface
10 thereby determined. The shear strength values were determined
after 24 hours' storage in water at 3i C according to ISO-TR 11
405. The adhesive strength ascertained in the shear test gave
an excellent value of 11.6 + 2.0 MPa.
