Novel silicone-substituted cinnamamide/malonamide/malonate compounds having the structural formulae (1) and (2): ##STR1## in which A is a radical of formula (3): ##STR2## are well suited for the photoprotection of human skin and/or hair against the damaging effects of UV-A and UV-B irradiation, particularly solar radiation, and are also useful for photoprotecting such UV-sensitive substrates as plastics.

CROSS-REFERENCE TO COMPANION APPLICATION 
Our copening application Serial No. 08/969,365 Nov. 28, 1997 filed 
concurrently herewith and assigned to the assignee hereof. 
BACKGROUND OF THE INVENTION 
1. Technical Field of the Invention 
The present invention relates to novel cinnamamide, benzalmalonamide and 
benzalmalonate compounds bearing short-chain silicone substituents on the 
aromatic moieties thereof. 
This invention also relates to compositions of matter, in particular 
cosmetic compositions, comprising the above novel compounds, which are 
especially well suited for the photoprotection of the skin and/or the hair 
against the deleterious effects of UV radiation, in particular solar 
radiation. 
2. Description of the Prior Art 
It is known to this art that light radiation of wavelengths of from 280 nm 
to 400 nm promotes tanning of the human epidermis, and that light 
radiation of wavelengths more particularly of from 280 to 320 nm, i.e., 
UV-B irradiation, causes skin burning and erythema which can impair the 
development of a natural tan. For these reasons, as well as for aesthetic 
reasons, there is an increasing demand for means of controlling this 
natural tanning in order to thereby control the color of the skin. This 
UV-B radiation must thus be screened from the skin. 
It is also known to this art that UV-A radiation, of wavelengths of from 
320 to 400 nm, which tan the skin, also adversely affects it, especially 
in the case of sensitive skin or skin which is continually exposed to 
solar radiation. UV-A rays especially cause a loss in the elasticity of 
the skin and the appearance of wrinkles, promoting premature skin aging. 
Such irradiation promotes triggering of the erythemal reaction or 
amplifies this reaction in certain individuals and may even be the source 
of phototoxic or photoallergic reactions. Thus, for aesthetic and cosmetic 
reasons, such as conservation of the natural elasticity of the skin, for 
example, an ever-increasing number of individuals wish to control the 
effect of UV-A rays on their skin, it is desirable to also screen out UV-A 
radiation. 
A wide variety of compounds suited for photoprotection (UV-A and/or UV-B) 
of the skin are known to this art. 
Most of these are aromatic compounds exhibiting absorption of UV radiation 
in the region from 280 to 315 nm, or in the region from 315 to 400 nm, or 
in both of these regions. They are typically formulated into antisun or 
sunscreen compositions which are in the form of an emulsion of 
oil-in-water type (namely, a cosmetically acceptable vehicle, diluent or 
carrier comprising a dispersing continuous aqueous phase and a dispersed 
discontinuous oily phase) and which thus contain, in various 
concentrations, one or more conventional lipophilic and/or hydrophilic 
organic screening agents including an aromatic function. These are capable 
of selectively absorbing harmful UV radiation, such screening agents (and 
their amounts) being selected as a function of the desired sun protection 
factor SPF (the sun protection factor being expressed mathematically by 
the ratio of the irradiation time required to attain the erythema-forming 
threshold with the UV screening agent to the time required to attain the 
erythema-forming threshold in the absence of UV screening agent). 
Other than their screening power, these compounds exhibiting anti-UV 
activity must also have good cosmetic properties in compositions comprised 
thereof, good solubility in the usual solvents, and in particular fatty 
substances such as oils and greases, as well as good resistance to water 
and to perspiration (remanence). 
Among all of the aromatic compounds which are suited for this purpose, 
particularly well suited are the silicon-containing benzalmalonate 
compounds described in EP-A-358,584 and in EP-A-392,882, both assigned to 
the assignee hereof. Admittedly, these compounds have good liposolubility. 
However, they also comprise very long silicone chains and, taking account 
of their bulk, their synthesis, as well as their formulation into cosmetic 
compositions, is not without difficulty. Lastly, their cosmetic properties 
are not always satisfactory. 
SUMMARY OF THE INVENTION 
A major object of the present invention is the provision of novel 
cinnamamide, benzalmalonamide and benzalmalonate compounds bearing 
short-chain silicone substituents on the aromatic moieties thereof, these 
novel compounds having, besides very good solubility in fatty materials, 
improved cosmetic properties, and which otherwise avoid those 
disadvantages and drawbacks to date characterizing the state of this art. 
Even more specifically, it has now been found that by grafting at least one 
cinnamamide, benzalmalonamide or benzalmalonate group onto a short-chain 
silicone molecule, in particular onto a linear silicone chain comprising 
not more than six Si atoms, novel compounds are obtained which obviate the 
drawbacks of the screening agents of the prior art, these novel compounds 
having, other than very high-performance screening properties, very good 
solubility in the usual organic solvents and in particular fatty 
substances such as oils, as well as excellent cosmetic properties, which 
render them particularly suitable for use as sunscreens in, or for the 
formulation of, cosmetic compositions suited for protecting the skin 
and/or the hair against the deleterious effects of ultraviolet radiation. 
And, taking account of their relatively small size, these novel compounds 
are easier to synthesize. 
Thus, the present invention features novel compounds having one of the 
formulae (1) or (2) below: 
##STR3## 
in which the radicals R, which may be identical or different, are each a 
saturated or unsaturated, linear or branched C.sub.1 -C.sub.10 alkyl 
radical, a phenyl radical or a 3,3,3-trifluoropropyl radical, at least 80% 
by number of the radicals R being methyl radicals; the radicals B, which 
may be identical or different, are each a radical R or a radical A; r is 
an integer ranging from 0 to 3, inclusive; s is 0 or 1 and if s is 0, at 
least one of the two radicals B is A; u is equal to 1 or 2; t is an 
integer ranging from 2 to 5 inclusive; t+u is greater than or equal to 3; 
and A is a radical of formula (3) below: 
##STR4## 
wherein R.sub.1 is a linear or branched C.sub.1 -C.sub.10 alkoxy radical, 
a linear or branched C.sub.1 -C.sub.10 alkyl radical, a linear or branched 
C.sub.2 -C.sub.8 alkenyl radical or a radical --OSi(CH.sub.3).sub.3, with 
the proviso that two adjacent radicals R.sub.1 may together form an 
alkylidenedioxy radical in which the alkylidene radical has from 1 to 2 
carbon atoms, n is 0, 1, 2 or 3, Z is hydrogen, a C.sub.1 -C.sub.4 alkyl 
radical, a radical --(C.dbd.O)XR.sub.2 or a radical --(C.dbd.O)YW, X and 
Y, which may be identical or different, are each an oxygen atom or a 
radical --NR.sub.3, W is a saturated or unsaturated, linear or branched 
C.sub.1 -C.sub.6 alkanediyl radical, optionally substituted with a 
hydroxyl or saturated or unsaturated, linear or branched C.sub.2 -C.sub.8 
alkyl radical, R.sub.2 is, independently, a C.sub.1 -C.sub.12 alkyl 
radical, R.sub.3 is, independently, hydrogen or a linear or branched 
C.sub.1 -C.sub.8 alkyl radical, with the proviso that R.sub.2 and R.sub.3 
may together form a heterocycle, with the added proviso that when Z=H, 
then X is the radical --NR.sub.3 --. 
DETAILED DESCRIPTION OF BEST MODE AND SPECIFIC/PREFERRED EMBODIMENTS OF THE 
INVENTION 
More particularly according to the present invention, by the term 
"heterocycle" is preferably intended a piperidino, morpholino, pyrrolidino 
or piperazino radical, optionally substituted in the 4-position with a 
C.sub.1 -C.sub.6 alkyl radical. 
The compounds of the invention differ from those of EP-A-392,882 in that 
the silicone chain(s) grafted onto the aromatic moieties of the 
cinnamamide, benzalmalonamide or benzalmalonate basic nuclei have not more 
than six Si atoms when they are linear and not more than seven Si atoms 
when they are cyclic. Although, in this fashion, these compounds comprise 
a short-chain silicone, they have excellent liposolubility and can thus be 
used in large concentrations, which imparts to the final compositions very 
high protection factors. Moreover, they are distributed uniformly in 
conventional cosmetic media containing at least one fatty phase or a 
cosmetically acceptable organic solvent and can thus be topically applied 
to the hair or the skin to provide an effective protective film. 
Furthermore, their cosmetic properties are very good, i.e., in particular, 
these products are less sticky and provide more softness than the 
screening silicones of the prior art. 
In addition, the compounds of the invention have an excellent intrinsic 
screening power with regard to UV-A and UV-B ultraviolet radiation. 
These novel silicone-substituted cinnamamide, benzalmalonamide and 
benzalmalonate compounds are thus useful sunscreens for human skin and 
hair. They are also useful photoprotective agents for plastics. 
The cinnamamide, benzalmalonate or benzalmalonamide compounds of formula 
(1) or (2) advantageously have at least one of the following 
characteristics: 
R is methyl, 
B is methyl, 
r is 0 or 1, 
s is 1, 
t+u ranges from 3 to 5, 
n is 0 or 1, 
R.sub.1 is methoxy, 
R.sub.2 is methyl or ethyl, 
R.sub.3 is H. 
Preferably, the compounds according to the present invention are compounds 
of formula (1) or (2) having all of the following characteristics: 
R is methyl, 
B is methyl, 
r=0, 
s=1, 
R.sub.1 is methoxy. 
To prepare the compounds of formula (1) or (2), a synthesis can be employed 
(route A) by carrying out a hydrosilylation reaction starting with the 
corresponding siloxane derivative in which, for example, all the radicals 
A are hydrogen atoms. This derivative is referred to hereinbelow as the 
SiH derivative. 
The SiH groups can be present along the chain and/or at the ends of the 
chain. These SiH derivatives are compounds that are well known to the 
silicone arts and are generally commercially available. They are 
described, for example, in U.S. Pat. Nos. 3,220,972, 3,697,473 and 
4,340,709. 
The SiH compounds corresponding to those of formulae (1) and (2) can thus 
be represented by formulae (4) and (5) below: 
##STR5## 
in which R, r, s, t and u are as defined above in formulae (1) and (2); 
and the radicals B', which may be identical or different, are each a 
radical R or a hydrogen atom. 
A hydrosilylation reaction is carried out of this SiH derivative of formula 
(4) or (5) in the presence of a catalytically effective amount of a 
platinum catalyst, on an organic compound selected from among those of 
formula (6) below: 
##STR6## 
in which R.sub.1, X, Z and n are as defined in formula (3) above and in 
which W' has the same definition as W in formula (3) above, but is 
terminated either with a double bond or with a triple bond. 
The hydrosilylation reaction is thus carried out according to one of the 
following two reaction mechanisms: 
##STR7## 
The compounds of formula (6) are thus the following compounds: 
(1) benzalmalonate compounds having the following formula: 
##STR8## 
in which R.sub.1, R.sub.2, W' and n are as defined in formula (6) above, 
(2) benzalmalonamide compounds having the following formulae: 
##STR9## 
in which R.sub.1, R.sub.2, R.sub.3, W' and n are as defined in formula (6) 
above, 
(3) cinnamamide compounds having the following formula: 
##STR10## 
in which R.sub.1, R.sub.3, W' and n are as defined in formula (6) above. 
Thus, benzalmalonate derivatives which are particularly suitable for the 
preparation of compounds according to the invention include diallyl 
4-methoxybenzylidenemalonate, described in FR-2,483,401, and diallyl 
benzylidenemalonate, described in Liebigs Ann. Chem., 1483 (1978). 
Exemplary cinnamamide compounds which are particularly suitable for the 
preparation of the compounds according to the invention, include 
N-allyl-3,4-dimethoxycinnamamide, described in J. Med. Chem., 7, 319 
(1964) and in JP-04,134,028, N-allyl-3,4,5-trimethoxycinnamamide, 
described in U.S. Pat. No. 3,268,407, and 
N-allyl-3-methoxy-4-octyloxycinnamamide, described in Acta Pharm. Hung., 
39, 66 (1969). 
Another route (route B) for the synthesis of the compounds of formulae (1) 
and (2) entails carrying out a hydrosilylation reaction on the SiH 
derivatives of formula (4) or (5) in the presence of a catalytically 
effective amount of a platinum catalyst, on an organic compound having the 
formula (7) below: 
##STR11## 
in which Z, X and W' are as defined in formula (6) above. 
The silicone derivative thus obtained, of formula (7') or (7") below: 
##STR12## 
is then reacted with a benzaldehyde of formula (8) below: 
##STR13## 
in which formulae (7), (7') and (8) X, W', Z, R.sub.1 and n are as defined 
above. 
The compounds of formula (7) in the event that X=O are prepared by 
alkylation of the corresponding acid with a halide of an unsaturated 
derivative (Hal) in the presence of a base, according to the following 
reaction scheme: 
EQU ZCH.sub.2 COOH+Hal-W'+NaOH.fwdarw.(7)+Hal-Na 
The compounds of formula (7) in the event that X=NR.sub.3 are prepared by 
reaction of the corresponding acid chloride with an unsaturated amine 
according to the following reaction scheme: 
EQU ZCH.sub.2 COCI+HNR.sub.3 --W'.fwdarw.(7)+HCl 
Another route (route C) for the preparation of the compounds of formulae 
(1) and (2) in which X is the --NH-- radical entails first reacting the 
derivative of formula (9) below: 
##STR14## 
with an aminosiloxane of formula (10) or (11) below: 
##STR15## 
in which R, r, s, t and u are as defined in formulae (1) and (2), and the 
radicals B', which may be identical or different, are each a radical R or 
an --NH.sub.2 radical. 
The preparation of the compounds of formula (9), such as 4-methoxycinnamyl 
chloride, is described in particular in Farmacia, 9, pages 345-350 (1961). 
The preparation of the aminosiloxanes is described, for example, in GB 
2,185,984. Exemplary aminosiloxanes which are particularly suitable for 
the preparation of the compounds according to the invention include 
aminopropylhepta-methyltrisiloxane, aminoisobutylheptamethyltrisiloxane 
and trimethylsilylamodimethicones, such as the product marketed under the 
trademark "X.sub.2 -8260" by Dow Corning, having an amine index of 2.8 
meq/gram; the product marketed under the trademark "SLM 55051/3" by 
Wacker, having an amine index of 0.47 meq/gram; C.sub.12 dimethylalkyl 
PDMSs, such as the product marketed under the trademark "SLM 23046/1" by 
Wacker, having an amine index of 1.2 meq/gram; .alpha., 
.omega.-trimethylated polymethylalkyl (fatty) arylalkylsiloxanes, such as 
the product marketed under the trademark "SLM 23056/2" by Wacker, having 
an amine index of 1.3 meq/gram; PDMSs whose NH.sub.2 radical is in 
position .alpha. and .omega. on an alkyl site, such as the products 
marketed under the trademarks "Tegomer A-SI 2120", having an amine index 
of 1.95 meq/gram and "Tegomer A-SI 2320" with an amine index of 0.86 
meq/gram, marketed by Goldschmidt. 
The preparation of the cyclic aminosiloxanes is described, for example, in 
the article by A. Kopylov, Zh. Obshch. Khim., 54 (2), 367-71 (1984). 
The present invention also features compositions comprising a compound of 
formula (1) or (2) formulated into a suitable support or medium therefor. 
The support can be, for example, a plastic. It can also be suitable for 
topical application. In this instance, the composition according to the 
invention is a cosmetic composition which comprises a cosmetically 
acceptable vehicle, diluent or carrier. 
Preferably, the compositions according to the invention are formulated to 
protect sensitive material against ultraviolet radiation, in particular 
solar radiation, comprising an effective amount of at least one compound 
of formulae (1) or (2). In a preferred embodiment of the invention, such 
compositions are for the photoprotection of the skin and/or the hair. 
The compounds of formula (1) or (2) are generally formulated into the 
compositions of the invention in proportions of from 0.1% to 20% by 
weight, preferably from 0.5% to 10% by weight, relative to the total 
weight of the composition. 
The compositions according to the invention can, of course, contain one or 
more complementary hydrophilic or lipophilic sunscreens that are active in 
the UV-A and/or UV-B range (absorbers), other than the subject compounds. 
These complementary screening agents are advantageously selected, in 
particular, from among the cinnamic derivatives, salicylic derivatives, 
camphor derivatives, triazine derivatives, benzophenone derivatives, 
dibenzoylmethane derivatives, .beta.,.beta.-diphenylacrylate derivatives, 
p-aminobenzoic acid derivatives, and the screening polymers and screening 
silicones described in WO-93/04665. Other examples of organic screening 
agents are provided in EP-A-0,487,404. 
The compositions according to the invention may also contain agents for the 
artificial tanning and/or browning of the skin (self-tanning agents) such 
as, for example, dihydroxyacetone (DHA). 
The compositions according to the invention may also contain pigments or 
nanopigments (average size of the primary particles: generally ranging 
from 5 nm to 100 nm, preferably from 10 nm to 50 nm) of coated or uncoated 
metal oxides, for example nanopigments of titanium dioxide (amorphous or 
crystallized in rutile and/or anatase form), of iron oxide, of zinc oxide, 
of zirconium oxide or of cerium oxide, which are all UV-photoprotective 
agents that are per se well known to this art. Standard coating agents 
therefor, include, moreover, alumina and/or aluminum stearate. Such coated 
or uncoated metal oxide nanopigments are described, in particular, in 
EP-A-0,518,772 and EP-A-0,518,773. 
The subject photoprotective compositions may also comprise typical 
additives and adjuvants in the cosmetics field, such as fatty substances, 
organic solvents, silicones, thickeners, softeners, complementary 
sunscreens, anti-foaming agents, moisturizers, fragrances, preservatives, 
surfactants, fillers, sequestering agents, anionic, cationic, nonionic or 
amphoteric polymers, or mixtures thereof, propellants, basifying or 
acidifying agents, dyes, colorants, pigments or nanopigments, in 
particular those intended to ensure a complementary photoprotective effect 
by physically blocking ultraviolet radiation, or any other ingredient 
usually used in cosmetics, in particular for the formulation of sunscreen 
compositions. 
Among the organic solvents, exemplary are the lower alcohols and polyols 
such as ethanol, isopropanol, propylene glycol, glycerol and sorbitol. 
Exemplary fatty substances include an oil or a wax or mixtures thereof, 
fatty acids, fatty acid esters, fatty alcohols, petroleum jelly, paraffin, 
lanolin, hydrogenated lanolin or acetylated lanolin. The oils can be 
selected from among animal, plant, mineral or synthetic oils, and in 
particular hydrogenated palm oil, hydrogenated castor oil, liquid 
petroleum jelly, liquid paraffin, purcellin oil, volatile or non-volatile 
silicone oils, and isoparaffins. 
Naturally, one skilled in this art will take care to select the optional 
complementary compound(s) indicated above and/or the amounts thereof such 
that the advantageous properties intrinsically associated with the 
compounds of this invention are not, or are not substantially, adversely 
affected by the addition(s) envisaged. 
The cosmetic compositions of the invention are well suited for protecting 
the human epidermis or the hair against the damaging effects of 
ultraviolet rays, whether as a sunscreen composition or as a makeup 
product. 
The subject compositions are advantageously formulated as lotions, 
thickened lotions, gels, creams, milks, powders or as solid sticks and 
can, optionally, be packaged as an aerosol and be in the form of a foam or 
a spray. 
When the cosmetic compositions according to the invention are more 
particularly intended for protecting the human epidermis against UV 
irradiation or as sunscreen compositions, they can be formulated as 
suspensions or dispersions in solvents or fatty substances, or as 
emulsions (in particular of O/W or W/O type, but preferably O/W type) such 
as a cream or a milk, a vesicle dispersion, or as ointments, gels, solid 
sticks or aerosol foams. The emulsions can also contain anionic, nonionic, 
cationic or amphoteric surfactants. 
When the cosmetic compositions according to the invention are used to 
protect the hair, they may be in the form of a shampoo, a lotion, a gel or 
a rinse-out composition to be applied before or after shampooing, before 
or after dyeing or bleaching, before, during or after permanent-waving or 
straightening of the hair, a styling or treating lotion or gel, a 
blow-drying or hair-setting lotion or gel, a hair lacquer or a composition 
for permanent-waving, straightening, dyeing or bleaching the hair. 
When the cosmetic compositions according to the invention are formulated as 
makeup products for the eyelashes, the eyebrows, the skin or the hair, 
such as skin treatment creams, foundations, lipsticks, eyeshadows, 
blushers, eyeliners, mascara or coloring gels, same may be in anhydrous or 
aqueous, solid or pasty form, for example oil-in-water or water-in-oil 
emulsions, suspensions or, alternatively, gels. 
This invention also features the subject compounds formulated into 
compositions well suited for photoprotecting sensitive material against 
ultraviolet radiation, in particular solar radiation. 
This invention also features formulating a compound of formulae (1) or (2) 
into medicinal products for combatting the harmful effects of UV 
radiation. 
The present invention also features use of a compound of formula (1) or (2) 
as an agent for screening out UV radiation, in particular for controlling 
the color of the skin. 
Lastly, the present invention also features a non-therapeutic process for 
protecting the skin and/or the hair against the deleterious effects as 
ultraviolet radiation, in particular solar radiation, comprising applying 
to the skin or the hair an effective sunscreen amount of the cosmetic 
composition defined above, or of a compound of formula (1) or (2). 
Too, this invention features a non-therapeutic process for controlling the 
variation in skin color due to UV radiation, which includes applying to 
the skin an effective amount of the cosmetic composition defined above, or 
of a compound of formula (1) or (2). 
In order to further illustrate the present invention and the advantages 
thereof, the following specific examples are given, it being understood 
that same are intended only as illustrative and in nowise limitative.

EXAMPLE 1 
Preparation of 
4-methoxy-N-[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]pro 
pyl]cinnamamide according to route C 
##STR16## 
To a mixture of 
3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propylamine 
(27.96 g, 0.1 mol) and triethylamine (7.08 g, 0.07 mol) in 20 ml of 
dichloromethane was added dropwise para-methoxycinnamyl chloride (9.68 g, 
0.05 mol) over 30 minutes. The temperature increased to 35.degree. C. The 
mixture was refluxed for 3 hours. The reaction mixture was poured into 40 
ml of water and extracted with dichloromethane. The organic phases were 
washed with water, dried over sodium sulfate and the solvent was then 
evaporated off. After purification by passage through a column of silica 
(eluent: 70/30 heptane/ethyl acetate), 19.9 g (yield: 93%) of the compound 
having the following characteristics were obtained: 
(i) white powder 
(ii) m.p.: 80-81.degree. C. 
(iii) UV (ethanol) .lambda..sub.max =307 nm, .epsilon..sub.max =24,825 
Elemental analysis for C.sub.20 H.sub.37 N O.sub.4 Si.sub.3 theory: C: 
54.62 H: 8.48 N: 3.18 found: C: 54.50 H: 8.45 N: 3.10 
EXAMPLE 2 
Preparation of 
di[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-disiloxanyl]pro 
pyl]4-methoxybenzalmalonate According to Route B 
##STR17## 
(a) First Step: Preparation of 
Di[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)-oxy]disiloxanyl]pro 
pyl] malonate 
A solution of dimethallyl malonate (10 g, 0.047 mol) and catalyst (complex 
containing 3-3.5% by weight of Pt in cyclovinylmethylsiloxane, marketed by 
Huls under the trademark Petrarch PC085: 200 .mu.l) in 30 ml of toluene 
was heated to 80.degree. C. 23 g (0.104 mol) of heptamethyltrisiloxane 
were added dropwise thereto over 20 minutes. The mixture was heated at 
80.degree. C. for 16 hours. The solvent and the excess 
heptamethyltrisiloxane were evaporated off under vacuum. The 
di[2-methyl-3-[1,3,3,3-tetramethyl-1-[(tri-methylsilyl)oxy]disiloxanyl]pro 
pyl] malonate was thus obtained in the form of an oil, which was employed 
as is in the next step. 
(b) Second Step: Preparation of 
Di[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-disiloxanyl]pro 
pyl]4-methoxybenzalmalonate 
A mixture of the above compound (a) (10 g, 0.0234 mol) and anisaldehyde 
(2.72 g, 0.02 mol) in 20 ml of toluene was refluxed for 12 hours in the 
presence of 0.2 ml of piperidine and 0.12 ml of acetic acid. The reaction 
mixture was concentrated and chromatographed on silica (eluent: 50/50 
heptane/CH.sub.2 Cl.sub.2) in order to obtain 4.6 g of the target compound 
of Example 2 (yield: 30%) in the form of a colorless oil, characterized by 
its NMR and mass spectra: 
(i) Mass spectrum: m/z=775.3 (MH).sup.+ 
(ii) Proton NMR: presence of an impurity (4%) of 
[2-methyl-3-[1,3,3,3-tetramethyl-1-[(tri-methylsilyl)oxy]disiloxanyl]propy 
l] 4-methoxycinnamate: m/z=455.2 (MH).sup.+ 
(iii) UV (ethanol) .lambda..sub.max =310 nm, .epsilon..sub.max =21,040 
EXAMPLE 3 
Preparation of Methyl 
3-(4-methoxyphenyl)-2-(3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-disi 
loxanyl]propylcarbamoyl)acrylate 
##STR18## 
(a) First Step: Preparation of Methyl 
N-[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-disiloxanyl]propyl]malon 
amate 
To a mixture of 
3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propylamine 
(6.99 g, 0.025 mol) and triethylamine (20 g, 0.2 mol) in 20 ml of 
dichloromethane was added dropwise monomethyl malonyl chloride (3.4 g, 
0.025 mol) over 30 minutes at 10.degree. C. The reaction mixture was 
permitted to warm to room temperature and was refluxed for 2 hours. The 
reaction mixture was poured into 40 ml of water and extracted with 
dichloromethane. The organic phases were washed with water and dried over 
sodium sulfate and the solvent was then evaporated off. After purification 
by passage through a column of silica (eluent: 95/5 CH.sub.2 Cl.sub.2 
/methanol), 2.2 g of a colorless oil were obtained, which product was 
employed as is in the following step. 
(b) Second Step: Preparation of Methyl 
3-(4-methoxyphenyl)-2-(3-[1,3,3,3-tetramethyl-1-[(tri-methylsilyl)oxy]disi 
loxanyl]-propylcarbamoyl)acrylate 
A mixture of the above compound (a) (1 g, 0.003 mol) and anisaldehyde (0.45 
g, 0.0033 mol) in 1 ml of toluene was maintained at 80.degree. C. for 12 
hours in the presence of 0.03 g of piperidine and 0.018 g of acetic acid. 
The reaction mixture was concentrated and chromatographed on silica 
(eluent: 80/20 heptane/ethyl acetate) in order to obtain 1 g of the target 
compound of Example 3 in the form of a colorless oil, characterized by its 
NMR and mass spectra: 
(i) Mass spectrum: m/z=498 (MH).sup.+ 
(ii) UV (ethanol) .lambda..sub.max =312 nm, .epsilon..sub.max =21,470 
EXAMPLE 4 
One specific example of a sunscreen emulsion having the following 
composition is given below (the amounts are expressed in % by weight 
relative to the total weight of the composition): 
______________________________________ 
(a) 80/20 mixture of cetylstearyl 
7% 
alcohol and oxyethylenated cetylstearyl alcohol 
(33 EO) marketed under the trademark "Dehsconet 390" 
by Tensia, 
(b) mixture of glyceryl mono- and 2% 
distearate, marketed under the trademark "Cerasynth 
SD" by ISP, 
(c) cetyl alcohol 1.5% 
(d) polydimethylsiloxane marketed under the 1.5% 
trademark "DC200 Fluid" by Dow Corning, 
(e) C.sub.12 -C.sub.15 alkyl benzoate marketed under 15% 
the trademark "Finsolv TN" by Finetex, 
(f) compound of Example 2 5% 
(g) glycerol 20% 
(h) preservatives qs 
(i) demineralized water qs 100% 
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This O/W sunscreen emulsion was formulated according to standard techniques 
for the preparation of emulsions, by dissolving the screening agent in the 
fatty phase containing the emulsifiers, heating this fatty phase to about 
70-80.degree. C. and adding, with vigorous stirring, the water heated to 
the same temperature. Stirring was continued for 10 to 15 minutes, the 
mixture was then permitted to cool with moderate stirring, and lastly, at 
about 40.degree. C., the preservatives were added. 
A sunscreen cream particularly effective against UV radiation was thus 
obtained. 
While the invention has been described in terms of various preferred 
embodiments, the skilled artisan will appreciate that various 
modifications, substitutions, omissions, and changes may be made without 
departing from the spirit thereof. Accordingly, it is intended that the 
scope of the present invention be limited solely by the scope of the 
following claims, including equivalents thereof.