WO2010136360A2

WO2010136360A2 - Benzylidene malonates

Info

Publication number: WO2010136360A2
Application number: PCT/EP2010/056843
Authority: WO
Inventors: Markus Hansch; Thomas Ehlis; Olof Wallquist; Barbara Wagner; Bernd Herzog; Jochen Giesinger
Original assignee: Basf Se
Priority date: 2009-05-29
Filing date: 2010-05-19
Publication date: 2010-12-02
Also published as: US20120128745A1; EP2435017A2; KR20120018812A; KR20140112561A; KR20140114434A; CN102448429B; WO2010136360A3; EP2435017B1; BRPI1011417A2; KR101621638B1; ES2766259T3; CN102448429A; JP5722312B2; JP2012528098A

Abstract

Disclosed is the use of benzylidene malonates of formula (1), wherein R₁ is methyl; ethyl; propyl; or n-butyl; if R₁ is methyl, then R is tert. butyl; formula (A); a radical of formula (1a); or a radical of formula (1b); wherein R₂ and R₃, independently from each other are hydrogen; or methyl; R₄ is methyl; ethyl; or n-propyl; R₅ and R₆ independently from each other are hydrogen; or C₁-C₃alkyl; if R₁ is ethyl; propyl; or n-butyl, then R is isopropyl; for the protection of human and animal hair and skin against UV radiation.

Description

Benzylidene malonates

The present invention relates to the use of specific monomeric benzylidene malonates for cosmetic preparations and new monomeric benzylidene malonates.

It is well known that ultraviolet radiation (light) is harmful to human skin. Depending on the wavelength UV radiation causes different types of skin damage. UV-B radiation (about 290 to about 320 nm) is responsible for sunburn and can cause skin cancer. UV-A radiation (about 320 to about 400 nm) while producing tanning of the skin, contributes also to sunburn and the induction of skin cancers. Moreover, the harmful effects of the UV-B radiation may be aggravated by UV-A radiation.

Therefore, an effective sunscreen formulation preferably comprises both at least one UV-A and UV-B filter and a broad band UV filter covering the full range from about 290nm to about 400 nm to prevent the human skin from the damage of sunlight.

Besides their screening power on solar radiation UV filters must also have good resistance to water and perspiration and also satisfactory photostability.

Unfortunately, many effective organic UV filters have a poor oil-solubility at a certain concentration and tend to crystallization. As a consequence the UV protection efficacy is significantly decreased.

It is known that there are lipophilic UV filters like Butyl Methoxydibenzoylmethane (sold under the tradename "Parsol 1789" by DSM) which have the particularity and also the disadvantage of being solid at ambient temperature. As a result, their use in sunscreen cosmetic compositions implies certain constraints in terms of their formulation and their use, in particular the selection of specific suitable cosmetic solvents that afford a proper solubility of these UV filters. Thus, a UV filter should show high solubility in common cosmetic oils or should be a good solvent for other UV filters that show poor oil solubility.

Moreover the oil soluble UV filters should be included in cosmetic sun care products without any impact on the sensorial characteristic of the emulsion. For that reason the optimal distribution of the UV absorber within the hydro-lipid film left on the skin after spreading should be guaranteed. It is therefore an object of the present invention to find UV absorber formulations which have improved properties regarding the UV absorber.

Surprisingly it has been found that specific monomeric benzylidene malonates have very good properties as cosmetic UV-B absorbers.

Therefore, the present invention relates to the use of benzylidene malonates of formula

(1 ) , wherein

R₁ is methyl; ethyl; propyl; or n-butyl; if R₁ is methyl, then

R is tert. butyl; ; a radical of formula

(1a) : ; wherein

R₂ and R₃, independently from each other are hydrogen; or methyl;

R₄ is methyl; ethyl; or n-propyl;

R₅ and R₆ independently from each other are hydrogen; or CrC₃alkyl; if R₁ is ethyl; propyl; or n-butyl, then

R is isopropyl; for the protection of human and animal hair and skin against UV radiation.

Preferably compounds of formula (1 ) are used, wherein R₁ is methyl; ethyl; propyl; or n-butyl; if R₁ is methyl, then R is tert. butyl; ; a radical of formula (1a) ; or a

radical of forumula (1 b)

R₂ and R₃, independently from each other are hydrogen; or methyl; R₄ is methyl; ethyl; or n-propyl;

R₅ and R₆ independently from each other are hydrogen; or d-C₃alkyl; if R₁ is ethyl; propyl; or n-butyl, then R is isopropyl.

Prefereably, in formula (1 )

R is a radical of formul

R₁ is methyl.

Most preferred are compounds of formula (1 ), wherein in formula (1a) at least one of R₂ or R₃ is methyl.

Most preferred are also compounds of formula (1 ), wherein in formula (1 a) R₂ and R₃ are methyl.

Preferred are also compounds, wherein R₁ is ethyl; propyl; or n-butyl; and R is isopropyl.

Examples of compounds of formula (1 ) are listed in the Table 1 below: Table 1 : Examples of monomeric benzylidene malonates according to the present invention

R₁ R

MB M-01 methyl

MBM-02 methyl

MBM-03 methyl

MBM-04 methyl

MBM-05 methyl

MBM-06 methyl

MBM-07 methyl

MBM-08 methyl

MBM-09 methyl

MBM-10 ethyl

MBM-1 1 propyl

MBM-12 n-butyl Table 1 : Examples of monomeric benzylidene malonates according to the present invention

MBM-13 methyl

The present invention also refers to novel monomeric benzylidene compounds. These compounds correspond to formula

(V) , wherein

R^ methyl; ethyl; propyl; or n-butyl; if R'-i is methyl, then

R' is tert. butyl; or a radical of formula (Va) ; or a

radical of forumula (Vb)

R'₂ and R'₃, independently from each other are hydrogen; or methyl; R'₄ is methyl; ethyl; or n-propyl; if R^ is ethyl; or propyl; then R' is isopropyl.

Preferred are benzylidene malonates according of formula (V), wherein R'i is methyl.

Most preferred are benzylidene malonates according of formula (V), wherein R'₂ and R'3 are methyl. Even more preferred are benzylidene malonates according of formula (1 '), wherein

R' is a radical of formula

R'i is methyl.

Preferred are also benzylidene malonates of formula (1 '), wherein R'i is ethyl, ethyl; propyl; or n-butyl; and R' is isopropyl.

The benzylidene malonates according to the present invention are prepared in a manner known per se according to the following reaction scheme:

The Knoevenagel condensation under conditions (a) is carried out under azeotropic removal of water in the presence of a catalyst (literature: Jones, Gurnos. Knoevenagel condensation. Organic Reactions (New York) 15, 204-599 (1967).

Solvents used in this step are for example benzene, toluene, o-xylene, m-xylene, p-xylene, chloroform, dichloromethane, ethanol, methanol, tetrahydrofurane, acetonitrile, ethyl acetate, CCI₄, cyclohexane, n-hexane, n-pentane, or ionic liquids as for example 1-methyl-3-butyl imidazolium bromide. Mixtures of solvents can also be used.

The reaction temperature is preferably between 0⁰C and the reflux temperature of the solvent mixture, preferably between 0⁰C and 180⁰C, and more preferably between 20° and 150⁰C. The reaction time is preferably from 5min to 72h, and more preferably from 1 to10h.

The catalysts used in this reaction step are preferably primary, secondary or tertiary amines like piperidine, n-hexylamine, pyridine or triethylamine. The basic amines can be used as such or in combination with an acidic compound like acetic acid, benzoic acid or HCI. Suitable catalysts are any catalysts which are normally used in Knoevenagel reactions. Preferably are used catalysts such as a salt of an organic base with an organic acid, such as piperidinium acetate.

The Knoevenagel condensation under conditions (b) is carried out in the presence of a tetra- alkyl orthotitanate Ti(OR^') (0.5 req. to 5 eq. with respect to the aldehyde) as decribed for example in K. Yamashita et al., Tetrahedron 2005, 61, 7981-7985. Solvents used in this step are alcohols ROH, for example ethanol, methanol, isopropanol, n-propanol, n-butanol, 2- methyl-1-butanol, isobutanol, 2-butanol, 2-pentanol. Other suitable solvents are benzene, toluene, o-xylene, m-xylene, p-xylene, chloroform, dichloromethane, tetrahydrofurane, acetonitrile, ethyl acetate, CCI₄, cyclohexane, n-hexane, n-pentane, or ionic liquids as for example 1-methyl-3-butyl imidazolium bromide. Mixtures of solvents can also be used. The reaction temperature is preferably between -10⁰C and the reflux temperature of the solvent mixture, preferably between 0°C and 180°C, and more preferably between 20° and 150⁰C.

The Knoevenagel condensation under conditions (c) is carried out in the presence of a titanium tetrachloride TiCI₄ (0.5 req. to 5 eq. with respect to the aldehyde) as decribed for example in W. Lehnert, Tetrahedron Letters 1970, 54, 4723-4724 or in H. Chen et al., Eur. J. Org. Chem. 2006, 2329-2335. Solvents used in this step are ethers like tetrahydrofurane, dioxane, tert-butyl-methylether, diethyl ether, or alcohols ROH, for example ethanol, methanol, isopropanol, n-propanol, n-butanol, 2-methyl-1-butanol, isobutanol, 2-butanol, 2- pentanol. Other suitable solvents are benzene, toluene, o-xylene, m-xylene, p-xylene, chloroform, dichloromethane, tetrahydrofurane, acetonitrile, ethyl acetate, CCI₄, cyclohexane, n-hexane, n-pentane, or ionic liquids as for example 1-methyl-3-butyl imidazolium bromide. Mixtures of solvents can also be used.

The reaction temperature is preferably between -10⁰C and the reflux temperature of the solvent mixture, preferably between 0⁰C and 180⁰C, and more preferably between 20° and 150⁰C.

The monomeric benzylidene malonates according to formula (1 ) are suitable especially as UV filters, that is to say for the protection of organic materials that are sensitive to ultraviolet light, especially human and animal skin and hair, against the action of UV radiation. Such compounds are accordingly suitable as light-protective agents in cosmetic, pharmaceutical and veterinary medicine preparations. Such compounds are preferably used in the dissolved state.

The invention accordingly relates also to a cosmetic preparation comprising at least one compound of formula (1 ), and cosmetically tolerable carriers or adjuvants.

The cosmetic preparation may also comprise, in addition to the UV absorber according to the invention, one or more further UV protective agents of the following substance classes: p-aminobenzoic acid derivatives, salicylic acid derivatives, benzophenone derivatives, diben- zoylmethane derivatives, diphenylacrylates, 3-imidazol-4-yl acrylic acid and esters; benzo- furan derivatives, polymeric UV absorbers, cinnamic acid derivatives, camphor derivatives, hydroxyphenyltriazine compounds, benzotriazole compounds, trianilino-s-triazine derivatives, 2-phenylbenzimidazole-5-sulfonic acid and salts thereof; menthyl o-aminobenzoate; merocy- anine derivatives; encapsulated UV absorbers, 4,4-diphenyl-1 ,3-butadiene derivatives, tris- (aryl) triazines, TiC>2, ZnO and mica.

The UV absorbers described in "Sunscreens", Eds. NJ. Lowe, N.A.Shaath, Marcel Dekker, Inc. , New York and Basle or in Cosmetics & Toiletries (107), 50ff (1992) also can be used as additional UV protective substances. Special preference is given to the light-protective agents indicated in the following Table 2:

Table 3: Suitable UV filter substances which can be additionally used with the UV absorbers according to the present invention

(Abbreviations T: Table, R: row, Comp: compound, Ex: compound(s) of Patent Example, p: page; the generic scope of the UV absorbers is described in the left-hand column; specific compounds are indicated in the right-hand column)

WO2009038463 | Comp. 4 on p. 33; Comp. 5 on p. 35; Ex. 2-9 on pp. 36-37

In addition, BEMT (Tinosorb S, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine) encapsulated in a polymer matrix, for example in PMMA, as described in IP.com Journal (2009), 9(1 B), 17, can also be used as additional UV protective substance.

The following compounds can also be used as additional UV protective substances:

Each of the above-mentioned light-protective agents, especially the light-protective agents in the above Tables indicated as being preferred, can be used in admixture with the UV absorbers according to the invention. It will be understood in that connection that, in addition to the UV absorbers according to the invention, it is also possible for more than one of the additional light-protective agents to be used, for example, two, three, four, five or six further light- protective agents. Preference is given to the use of mixing ratios of UV absorbers according to the invention/further light-protective agents of from 1 :99 to 99:1 , especially from 1 :95 to 95:1 and preferably from 10:90 to 90:10, based on weight. Of special interest are mixing ratios of from 20:80 to 80:20, especially from 40:60 to 60:40 and preferably of approximately 50:50. Such mixtures can be used, inter alia, to improve solubility or to increase UV absorption.

Appropriate mixtures can be used especially advantageously in a cosmetic composition according to the invention.

Preferably, the benzylidene malonates according to the present invention are used - in combination with at least one additional oil soluble UV filter in combination with at least one additional water soluble UV filter in combination with at least one additional insoluble soluble UV filter in combination with at least one additional insoluble organic UV filter in combination with at least one additional insoluble inorganic UV filter in combination with at least one additional organic UV filter in combination with at least one additional inorganic UV filter in combination with at lest one additional organic/inorganid hybrid material UV filter in combination with at lest one additional encapsulated UV filter in combination with at lest one additional polymeric UV filter.

The following mixtures of oil miscible organic UV filters (Table 4) can be mixed together with the benzylidene malonates according to the present invention:

The following mixtures of aqueous soluble or dispersible UV filters (Table 5) can be mixed together with the benzylidene malonates according to the present invention:

UV filter combination examples

In all of the UV filter combinations listed before in the Table "X" represents a specific UV filter. The weight ratio of each specific UV absorber (based on the weight of all UV absorbers in the combination) can for example range from 0.01 to 0.99, especially 0.1 to 0.9, preferably 0.2 to 0.8. (for example 0.3).

Further UV filter combination examples are the following: In all of the UV filter combinations listed before the weight ratio of the UV absorbers (based on the weight of all UV absorbers in the combination) is:

(a) for combinations of two UV absorbers:

1:1 or 1:2 or 2:1 or 1:3 or 3:1.

(b) for combinations of three UV absorbers:

1:1:1 or 1:2:1 or 1:1:2 or 2:1:1 or 1:2:2 or 2:1:2 or 2:2:1 or 1:3:1 or 1:1:3 or 3:1:1 or 1:3:3 or 3:1:3 or 3:3:1 or 1:2:3 or 1:3:2 or 2:1:3 or 2:3:1 or 3:1:2 or 3:2:1.

(c) for combinations of four UV absorbers:

1:1:1:1 or 1:1:2:1 or 1:1:1:2 or 1:2:1:1 or 2:1:1:1 or

1:1:1:3 or 1:1:3:1 or 1:3:1:1 or 3:1:1:1 or 1:2:2:1 or 2:1:2:1 or 2:2:1:1 or 2:1:1:2 or

1:3:31 or 3:1:3:1 or 3:3:1:1 or 3:1:1:3 or 1:2:3:1 or

1:3:2:1 or 1:1:2:3 or 1:1:3:2 or 2:1:1:3 or 2:1:3:1 or 2:3:1:1 or 3:1:1.2 or

3:2:1:1 or 3:1:2:1.

Formulation examples

In the following formulation examples:

The new UV filter may be (as described in Table 1 ) MBM-01 or MBM-02 or MBM-03 or MBM- 04 or MBM-05 or MBM-06 or MBM-07 or MBM-081 or MBM-09 or MBM-10 or MBM-11 or MBM-12.

,,UV SOL" may be (as described in Table 2) UV SOL 1 , or UV SOL 2, or UV SOL 3, or UV SOL 4, or UV SOL 5, or UV SOL 6, or UV SOL 7, or UV SOL 8, or UV SOL 9, or UV SOL 10, or UV SOL 11, or UV SOL 12, or UV SOL 13, or UV SOL 14, or UV SOL 15, or UV SOL 16, or UV SOL 17, or UV SOL 18, or UV SOL 19, or UV SOL 20, or UV SOL 21 , or UV SOL 22, or UV SOL 23, or UV SOL 24, or UV SOL 25, or UV SOL 26, or UV SOL 27, or UV SOL 28, or UV SOL 29, or UV SOL 30, or UV SOL 31 , or UV SOL 32, or UV SOL 33, or UV SOL 34, or UV SOL 35, or UV SOL 36, or UV SOL 37, or UV SOL 38, or UV SOL 39, or UV SOL 40, or UV SOL 41 , or UV SOL 42, or UV SOL 43, or UV SOL 44, or UV SOL 45, or UV SOL 46, or UV SOL 47, or UV SOL 48, or UV SOL 49, or UV SOL 50, or UV SOL 51, or UV SOL 52, or UV SOL 53, or UV SOL 54, or UV SOL 55, or UV SOL 56, or UV SOL 57, or UV SOL 58, or UV SOL 59, or UV SOL 60, or UV SOL 61 , or UV SOL 62, or UV SOL 63, or UV SOL 64, or UV SOL 65, or UV SOL 66, or UV SOL 67, or UV SOL 68, or UV SOL 69, or UV SOL 70, or UV SOL 71 , or UV SOL 72, or UV SOL 73, or UV SOL 74, or UV SOL 75, or UV SOL 76, or UV SOL 77, or UV SOL 78, or UV SOL 79, or UV SOL 80, or UV SOL 81, or UV SOL 82, or UV SOL 83, or UV SOL 84, or UV SOL 85, or UV SOL 86, or UV SOL 87, or UV SOL 88, or UV SOL 89, or UV SOL 90, or UV SOL 91, or UV SOL 92, or UV SOL 93, or UV SOL 94, or UV SOL 95, or UV SOL 96, or UV SOL 97, or UV SOL 98, or UV SOL 99, or UV SOL 100, or UV SOL 101, or UV SOL 102, or UV SOL 103, or UV SOL 104, or UV SOL 105, or UV SOL 106, or UV SOL 107, or UV SOL 108, or UV SOL 109, or UV SOL 110, or UV SOL 111, or UV SOL 112, or UV SOL 113, or UV SOL 114, or UV SOL 115, or UV SOL 116, or UV SOL 117, or UV SOL 118, or UV SOL 119, or UV SOL 120, or UV SOL 121 , or UV SOL 122, or UV SOL 123, or UV SOL 124, or UV SOL 125, or UV SOL 126, or UV SOL 127, or UV

SOL 128, or UV SOL 129, or UV SOL 130, or UV SOL 131, or UV SOL 132, or UV SOL 133, or UV SOL 134, or UV SOL 135, or UV SOL 136, or UV SOL 137, or UV SOL 138, or UV SOL 139, or UV SOL 140, or UV SOL 141, or UV SOL 142, or UV SOL 143, or UV SOL 144, or UV SOL 145, or UV SOL 146, or UV SOL 147, or UV SOL 148, or UV SOL 149, or UV SOL 150, or UV SOL 151, or UV SOL 152, or UV SOL 153, or UV SOL 154, or UV SOL 155, or UV SOL 156, or UV SOL 157, or UV SOL 158, or UV SOL 159, or UV SOL 160, or UV SOL 161, or UV SOL 162, or UV SOL 163, or UV SOL 164, or UV SOL 165, or UV SOL 166, or UV SOL 167, or UV SOL 168, or UV SOL 169, or UV SOL 170, or UV SOL 171, or UV SOL 172, or UV SOL 173, or UV SOL 174, or UV SOL 175, or UV SOL 176, or UV SOL 177, or UV SOL 178, or UV SOL 179, or UV SOL 180, or UV SOL 181, or UV SOL 182, or UV

SOL 183, or UV SOL 184, or UV SOL 185, or UV SOL 186, or UV SOL 187, or UV SOL 188, or UV SOL 189, or UV SOL 190, or UV SOL 191, or UV SOL 192, or UV SOL 193, or UV SOL 194, or UV SOL 195, or UV SOL 196, or UV SOL 197, or UV SOL 198, or UV SOL 199, or UV SOL 200, or UV SOL 201 , or UV SOL 202, or UV SOL 203, or UV SOL 204, or UV SOL 205, or UV SOL 206, or UV SOL 207, or UV SOL 208, or UV SOL 209, or UV SOL 210, or UV SOL 211 , or UV SOL 212, or UV SOL 213, or UV SOL 214, or UV SOL 215, or UV SOL 216, or UV SOL 217, or UV SOL 218, or UV SOL 219, or UV SOL 220, or UV SOL 221 , or UV SOL 222, or UV SOL 223, or UV SOL 224, or UV SOL 225, or UV SOL 226, or UV SOL 227, or UV SOL 228, or UV SOL 229, or UV SOL 230, or UV SOL 231 , or UV SOL 232, or UV SOL 233, or UV SOL 234, or UV SOL 235, or UV SOL 236, or UV SOL 237, or UV SOL 238, or UV SOL 239, or UV SOL 240, or UV SOL 241 , or UV SOL 242, or UV SOL 243, or UV SOL 244, or UV SOL 245, or UV SOL 246, or UV SOL 247, or UV SOL 248, or UV SOL 249, or UV SOL 250, or UV SOL 251 , or UV SOL 252, or UV SOL 253;

,,UV LIQ" may be (as described in Table 3) UV LIQ 1 , or UV LIQ 2, or UV LIQ 3, or UV LIQ 4, or UV LIQ 5, or UV LIQ 6, or UV LIQ 7, or UV LIQ 8, or UV LIQ 9, or UV LIQ 10, or UV LIQ 1 1 , or UV LIQ 12, or UV LIQ 13, or UV LIQ 14, or UV LIQ 15, or UV LIQ 16, or UV LIQ 17, or UV LIQ 18, or UV LIQ 19, or UV LIQ 20, or UV LIQ 21 , or UV LIQ 22, or UV LIQ 23, or UV LIQ 24, or UV LIQ 25, or UV LIQ 26, or UV LIQ 27, or UV LIQ 28, or UV LIQ 29, or UV LIQ 30, or UV LIQ 31 , or UV LIQ 32, or UV LIQ 33, or UV LIQ 34, or UV LIQ 35, or UV LIQ 36, or UV LIQ 37, or UV LIQ 38, or UV LIQ 39, or UV LIQ 40, or UV LIQ 41 , or UV LIQ 42, or UV LIQ 43, or UV LIQ 44, or UV LIQ 45, or UV LIQ 46, or UV LIQ 47, or UV LIQ 48, or UV LIQ 49, or UV LIQ 50, or UV LIQ 51 , or UV LIQ 52, or UV LIQ 53, or UV LIQ 54, or UV LIQ 55, or UV LIQ 56, or UV LIQ 57, or UV LIQ 58, or UV LIQ 59, or UV LIQ 60, or UV LIQ 61 , or UV LIQ 62, or UV LIQ 63, or UV LIQ 64, or UV LIQ 65, or UV LIQ 66, or UV LIQ 67, or UV LIQ 68, or UV LIQ 69, or UV LIQ 70, or UV LIQ 71 , or UV LIQ 72, or UV LIQ 73, or UV LIQ 74, or UV LIQ 75, or UV LIQ 76, or UV LIQ 77, or UV LIQ 78, or UV LIQ 79, or UV LIQ 80, or UV LIQ 81 , or UV LIQ 82, or UV LIQ 83, or UV LIQ 84, or UV LIQ 85, or UV LIQ 86, or UV LIQ 87, or UV LIQ 88, or UV LIQ 89, or UV LIQ 90, or UV LIQ 91 , or UV LIQ 92, or UV LIQ 93, or UV LIQ 94, or UV LIQ 95, or UV LIQ 96, or UV LIQ 97, or UV LIQ 98, or UV LIQ 99, or UV LIQ 100, or UV LIQ 101 , or UV LIQ 102, or UV LIQ 103, or UV LIQ 104, or UV LIQ 105, or UV LIQ 106, or UV LIQ 107, or UV LIQ 108, or UV LIQ 109, or UV LIQ 1 10, or UV LIQ 11 1 , or UV LIQ 112, or UV LIQ 1 13, or UV LIQ 114, or UV LIQ 1 15, or UV LIQ 116, or UV LIQ 1 17, or UV LIQ 118, or UV LIQ 1 19, or UV LIQ 120, or UV LIQ 121 , or UV LIQ 122, or UV LIQ 123;

,,UV WAT" may be (as described in Table 4) UV WAT 1 , or UV WAT 2, or UV WAT 3, or UV WAT 4, or UV WAT 5, or UV WAT 6, or UV WAT 7, or UV WAT 8, or UV WAT 9, or UV WAT 10, or UV WAT 1 1 , or UV WAT 12, or UV WAT 13, or UV WAT 14, or UV WAT 15, or UV WAT 16, or UV WAT 17, or UV WAT 18, or UV WAT 19, or UV WAT 20, or UV WAT 21 , or UV WAT 22, or UV WAT 23, or UV WAT 24, or UV WAT 25, or UV WAT 26, or UV WAT 27, or UV WAT 28, or UV WAT 29, or UV WAT 30, or UV WAT 31 , or UV WAT 32, or UV WAT 33, or UV WAT 34, or UV WAT 35, or UV WAT 36, or UV WAT 37, or UV WAT 38, or UV WAT 39, or UV WAT 40, or UV WAT 41 , or UV WAT 42, or UV WAT 43, or UV WAT 44, or UV WAT 45, or UV WAT 46, or UV WAT 47, or UV WAT 48, or UV WAT 49, or UV WAT 50, or UV WAT 51 , or UV WAT 52, or UV WAT 53, or UV WAT 54, or UV WAT 55, or UV WAT 56, or UV WAT 57, or UV WAT 58, or UV WAT 59, or UV WAT 60, or UV WAT 61 , or UV WAT 62, or UV WAT 63, or UV WAT 64, or UV WAT 65, or UV WAT 66, or UV WAT 67, or UV WAT 68, or UV WAT 69, or UV WAT 70, or UV WAT 71 , or UV WAT 72, or UV WAT 73, or UV WAT 74, or UV WAT 75, or UV WAT 76, or UV WAT 77, or UV WAT 78, or UV WAT 79, or UV WAT 80, or UV WAT 81 , or UV WAT 82, or UV WAT 83, or UV WAT 84, or UV WAT 85, or UV WAT 86, or UV WAT 87, or UV WAT 88, or UV WAT 89, or UV WAT 90, or UV WAT 91 , or UV WAT 92, or UV WAT 93, or UV WAT 94, or UV WAT 95, or UV WAT 96, or UV WAT 97, or UV WAT 98, or UV WAT 99, or UV WAT 100, or UV WAT 101 , or UV WAT 102, or UV WAT 103, or UV WAT 104, or UV WAT 105, or UV WAT 106, or UV WAT 107, or UV WAT 108, or UV WAT 109, or UV WAT 110, or UV WAT 1 11 , or UV WAT 1 12, or UV WAT 113, or UV WAT 114, or UV WAT 1 15, or UV WAT 1 16, or UV WAT 1 17, or UV WAT 1 18, or UV WAT 1 19, or UV WAT 120, or UV WAT 121 , or UV WAT 122, or UV WAT 123, or UV WAT 124, or UV WAT 125, or UV WAT 126, or UV WAT 127, or UV WAT 128, or UV WAT 129, or UV WAT 130, or UV WAT 131 , or UV WAT 132, or UV WAT 133, or UV WAT 134, or UV WAT 135, or UV WAT 136, or UV WAT 137, or UV WAT 138, or UV WAT 139, or UV WAT 140, or UV WAT 141 , or UV WAT 142, or UV WAT 143, or UV WAT 144, or UV WAT 145, or UV WAT 146, or UV WAT 147, or UV WAT 148, or UV WAT 149, or UV WAT 150, or UV WAT 151 , or UV WAT 152, or UV WAT 153, or UV WAT 154, or UV WAT 155, or UV WAT 156, or UV WAT 157, or UV WAT 158, or UV WAT 159, or UV WAT 160, or UV WAT 161 , or UV WAT 162, or UV WAT 163, or UV WAT 164, or UV WAT 165, or UV WAT 166, or UV WAT 167, or UV WAT 168, or UV WAT 169, or UV WAT 170, or UV WAT 171 , or UV WAT 172, or UV WAT 173, or UV WAT 174, or UV WAT 175, or UV WAT 176, or UV WAT 177, or UV WAT 178, or UV WAT 179, or UV WAT 180, or UV WAT 181 , or UV WAT 182, or UV WAT 183, or UV WAT 184, or UV WAT 185, or UV WAT 186, or UV WAT 187, or UV WAT 188, or UV WAT 189, or UV WAT 190, or UV WAT 191 , or UV WAT 192, or UV WAT 193, or UV WAT 194, or UV WAT 195, or UV WAT 196, or UV WAT 197, or UV WAT 198, or UV WAT 199, or UV WAT 200, or UV WAT 201 , or UV WAT 202, or UV WAT 203, or UV WAT 204, or UV WAT 205, or UV WAT 206, or UV WAT 207, or UV WAT 208, or UV WAT 209, or UV WAT 210, or UV WAT 211 , or UV WAT 212, or UV WAT 213, or UV WAT 214, or UV WAT 215, or UV WAT 216, or UV WAT 217, or UV WAT 218, or UV WAT 219, or UV WAT 220, or UV WAT 221 , or UV WAT 222, or UV WAT 223, or UV WAT 224, or UV WAT 225, or UV WAT 226, or UV WAT 227, or UV WAT 228, or UV WAT 229, or UV WAT 230, or UV WAT 231 , or UV WAT 232, or UV WAT 233, or UV WAT 234, or UV WAT 235, or UV WAT 236, or UV WAT 237, or UV WAT 238, or UV WAT 239, or UV WAT 240, or UV WAT 241 , or UV WAT 242, or UV WAT 243, or UV WAT 244, or UV WAT 245, or UV WAT 246, or UV WAT 247, or UV WAT 248, or UV WAT 249, or UV WAT 250, or UV WAT 251 , or UV WAT 252, or UV WAT 253, or UV WAT 254, or UV WAT 255, or UV WAT 256, or UV WAT 257, or UV WAT 258, or UV WAT 259, or UV WAT 260, or UV WAT 261 , or UV WAT 262, or UV WAT 263, or UV WAT 264, or UV WAT 265, or UV WAT 266, or UV WAT 267, or UV WAT 268, or UV WAT 269, or UV WAT 270, or UV WAT 271 , or UV WAT 272, or UV WAT 273, or UV WAT 274, or UV WAT 275, or UV WAT 276, or UV WAT 277, or UV WAT 278, or UV WAT 279, or UV WAT 280, or UV WAT 281 , or UV WAT 282, or UV WAT 283, or UV WAT 284, or UV WAT 285, or UV WAT 286, or UV WAT 287, or UV WAT 288, or UV WAT 289, or UV WAT 290, or UV WAT 291 , or UV WAT 292, or UV WAT 293, or UV WAT 294, or UV WAT 295, or UV WAT 296, or UV WAT 297, or UV WAT 298, or UV WAT 299, or UV WAT 300, or UV WAT 301 , or UV WAT 302, or UV WAT 303, or UV WAT 304, or UV WAT 305, or UV WAT 306, or UV WAT 307, or UV WAT 308, or UV WAT 309, or UV WAT 310, or UV WAT 31 1 , or UV WAT 312, or UV WAT 313, or UV WAT 314, or UV WAT 315, or UV WAT 316, or UV WAT 317, or UV WAT 318, or UV WAT 319, or UV WAT 320, or UV WAT 321 , or UV WAT 322, or UV WAT 323, or UV WAT 324, or UV WAT 325, or UV WAT 326, or UV WAT 327, or UV WAT 328, or UV WAT 329, or UV WAT 330, or UV WAT 331 , or UV WAT 332, or UV WAT 333, or UV WAT 334, or UV WAT 335, or UV WAT 336, or UV WAT 337, or UV WAT 338, or UV WAT 339, or UV WAT 340, or UV WAT 341 , or UV WAT 342, or UV WAT 343, or UV WAT 344, or UV WAT 345, or UV WAT 346, or UV WAT 347, or UV WAT 348, or UV WAT 349, or UV WAT 350, or UV WAT 351 , or UV WAT 352, or UV WAT 353, or UV WAT 354, or UV WAT 355, or UV WAT 356, or UV WAT 357, or UV WAT 358, or UV WAT 359, or UV WAT 360, or UV WAT 361 , or UV WAT 362, or UV WAT 363, or UV WAT 364, or UV WAT 365, or UV WAT 366, or UV WAT 367, or UV WAT 368, or UV WAT 369, or UV WAT 370, or UV WAT 371 , or UV WAT 372, or UV WAT 373, or UV WAT 374, or UV WAT 375, or UV WAT 376, or UV WAT 377.

Formulation Examples:

The invention relates also to cosmetic compositions that comprise at least one of the UV absorbers according to the invention. The cosmetic compositions are suitable especially as UV filters, that is to say for the protection of organic materials that are sensitive to ultraviolet light, especially skin and hair, against the damaging action of UV radiation.

The cosmetic compositions contain, for example, from 0.1 to 30 % by weight, preferably from 0.1 to 15 % by weight and especially from 0.5 to 10 % by weight, based on the total weight of the composition, of one or more UV absorbers and at least one cosmetically tolerable adjuvant.

The cosmetic compositions can be prepared by physically mixing the UV absorber(s) with the adjuvant using customary methods, for example by simply stirring together the individual components, especially by making use of the dissolution properties of already known cosmetic UV absorbers, for example OMC, salicylic acid isooctyl ester, inter alia. The UV absorber can be used, for example, without further treatment. The cosmetic compositions may be, for example, creams, gels, lotions, alcoholic and aqueous/alcoholic solutions, emulsions, wax/fat compositions, stick preparations, powders or ointments.

The compositions according to the invention, for example creams, gels, lotions, alcoholic and aqueous/alcoholic solutions, emulsions, wax/fat compositions, stick preparations, powders or ointments, may in addition contain, as further adjuvants and additives, mild surfactants, super-fatting agents, pearlescent waxes, consistency regulators, thickeners, polymers, silicone compounds, fats, waxes, stabilisers, biogenic active ingredients, deodorising active ingredients, anti-dandruff agents, film formers, swelling agents, further UV light-protective factors, antioxidants, hydrotropic agents, preservatives, insect repellents, self-tanning agents, solubilisers, perfume oils, colourants, bacteria-inhibiting agents and the like.

Cosmetic formulations according to the invention are contained in a wide variety of cosmetic preparations. There come into consideration, for example, especially the following preparations: skin-care preparations, bath preparations, skin-care preparations, cosmetic personal care preparations, foot-care preparations, light-protective preparations, skin-tanning preparations, depigmenting preparations, insect-repellents, deodorants, antiperspirants, preparations for cleansing and caring for blemished skin, hair-removal preparations in chemical form (depilation), shaving preparations, fragrance preparations, cosmetic hair- treatment preparations.

The final formulations listed may exist in a wide variety of presentation forms, for example:

- in the form of liquid preparations as a W/O, O/W, 0/W/O, W/O/W or PIT emulsion and all kinds of microemulsions,

- in the form of a gel,

- in the form of an oil, a cream, milk or lotion,

- in the form of a powder, a lacquer, a tablet or make-up,

- in the form of a stick, - in the form of a spray (spray with propellent gas or pump-action spray) or an aerosol,

- in the form of a foam, or

- in the form of a paste.

Of special importance as cosmetic compositions for the skin are light-protective preparations, such as sun milks, lotions, creams, oils, sunblocks or tropicals, pretanning preparations or after-sun preparations, also skin-tanning preparations, for example self-tanning creams. Of particular interest are sun protection creams, sun protection lotions, sun protection oils, sun protection milk and sun protection preparations in the form of a spray.

Of special importance as cosmetic compositions for the hair are the above-mentioned preparations for hair treatment, especially hair-washing preparations in the form of shampoos, hair conditioners, hair-care preparations, e.g. pretreatment preparations, hair tonics, styling creams, styling gels, pomades, hair rinses, treatment packs, intensive hair treatments, hair-straightening preparations, liquid hair-setting preparations, hair foams and hairsprays. Of special interest are hair-washing preparations in the form of shampoos.

The cosmetic preparation according to the invention contains from 0.1 to 15 % by weight, preferably from 0.5 to 10 % by weight, based on the total weight of the composition, of a UV absorber of formula (1 ) or of a mixture of UV absorbers and a cosmetically tolerable adjuvant.

The cosmetic preparation can be prepared by physically mixing the UV absorber or UV absorbers with the adjuvant using conventional methods, for example by simply stirring the individual components together.

The cosmetic preparation according to the invention can be formulated as a water-in-oil or oil-in-water emulsion, as an oil-in-alcohol lotion, as a vesicular dispersion of an ionic or non- ionic amphiphilic lipid, as a gel, solid stick or as an aerosol formulation.

As a water-in-oil or oil-in-water emulsion, the cosmetically tolerable adjuvant preferably contains from 5 to 50 % of an oil phase, from 5 to 20 % of an emulsifier and from 30 to 90 % water. The oil phase can comprise any oil suitable for cosmetic formulations, for example one or more hydrocarbon oils, a wax, a natural oil, a silicone oil, a fatty acid ester or a fatty alcohol. Preferred mono- or poly-ols are ethanol, isopropanol, propylene glycol, hexylene glycol, glycerol and sorbitol.

For the cosmetic preparation according to the invention it is possible to use any conventionally usable emulsifier, for example one or more ethoxylated esters of natural derivatives, for example polyethoxylated esters of hydrogenated castor oil, or a silicone oil emulsifier, for example silicone polyol; an unethoxylated or ethoxylated fatty acid soap; an ethoxylated fatty alcohol; an unethoxylated or ethoxylated sorbitan ester; an ethoxylated fatty acid; or an ethoxylated glyceride.

The cosmetic preparation according to the invention is distinguished by excellent protection of human skin against the damaging effect of sunlight.

In the following Examples percentages relate to weight. The amounts of the benzylidene malonates compounds used relate to the pure substance.

Preparation Examples

Example 1 : 4-Methoxybenzylidene-di-(2-methylbutyl)-malonate

In a flask with a distillation head a mixture of diethyl malonate (103 g, 0.637 mol), 2-methyl-1- butanol (284 g, 3.18 mol) and cone, sulfuric acid (95%, 12.9 g, 0.125 mol) is heated by an oil bath (bath temperature 160⁰C) for 3 h. During this time 120 ml of distillate are collected. The reaction mixture is cooled to room temperature and washed with water. After removing the excess of 2-methl-1-butanol under reduced pressure using a rotary evaporator di-(2- methylbutyl)-malonate (153 g, 98%) is obtained as a colourless liquid. The compound may be further purified by vacuum distillation (bp. 1 15-125°C/5 mbar).

¹H-NMR (360 MHz, CDCI₃): δ = 0.86-0.93 (m, 12 H), 1.12-1.24 (m, 2 H), 1.36-1.48 (m, 2 H), 1.65-1.78 (m, 2 H), 3.37 (s, 2 H), 3.93 (dd, J = 6.5 Hz, 10.5 Hz, 2 H), 4.03 (dd, J = 6.5 Hz,

10.5 Hz, 2 H); ¹³C-NMR (90 MHz, CDCI₃): δ = 11.06, 16.19, 25.84, 33.98, 41.62, 70.00, 166.6 ppm.

In a flask with a Dean-Stark apparatus a mixture of 4-methoxybenzaldehyde (67.4 g, 0.495 mol), di-(2-methylbutyl)-malonate (1 10 g, 0.450 mol) and n-hexylamine (4.7 g, 0.045 mol) is heated to reflux for 4 h. The reaction mixture is cooled to room temperature and the toluene is removed under reduced pressure using a rotary evaporator. Purification by Kugelrohr distillation under high vacuum yields 4-methoxybenzylidene-di-(2-methylbutyl)-malonate (136 g, 83%).

¹H-NMR (360 MHz, CDCI₃): δ = 0.87-0.95 (m, 12 H), 1.11-1.28 (m, 2 H), 1.36-1.51 (m, 2 H), 1.65-1.85 (m, 2 H), 3.83 (s, 3 H), 4.01-4.17 (m, 4 H), 6.88 (d, J = 8.5 Hz, 2 H), 7.41 (d, J = 8.5 Hz, 2 H), 7.66 (s, 1 H) ppm; ¹³C-NMR (90 MHz, CDCI₃): δ = 1 1.06, 1 1.14, 16.29, 25.85, 25.92, 33.90, 34.14, 55.30, 69.86, 70.27, 114.3, 123.7, 125.4, 131.5, 141.7, 161.5, 164.5, 167.4 ppm. The following examples are prepared in an analogues manner to Example 1 :

Example 13: 4-Methoxybenzylidene-di-(1-methylbutyl)-malonate

In a flask with a distillation head a mixture of diethyl malonate (32.Og, 0.200mol), 2-propanol (106g, 1.20mol) and Ti(OEt)₄ (9.1g, 0.040mol) is heated by an oil bath (bath temperature 160⁰C) for 14h, allowing the liberated ethanol to distill off.

The reaction mixture is cooled to room temperature before 0.5 M aq. HCI (200 ml) and EtOAc (200 ml) are added.

The phases are separated and the organic phase is washed with water (200ml), brine (200ml) and dried over Na₂SO₄.

After removing the solvent under reduced pressure using a rotary evaporator di-(1-methyl- butyl)-malonate (45.8g, 94%) is obtained as a colourless liquid. The compound may be further purified by vacuum distillation.

¹H-NMR (360 MHz, CDCI₃): δ = 0.90 (t, J = 7.5 Hz, 6 H), 1.22 (d, J = 6.5 Hz, 6 H), 1.27-1.51 (m, 6 H), 1.54-1.65 (m, 2 H), 3.30 (s, 2 H), 4.96 (sext, J = 6.5 Hz, 2 H). 1³C-NMR (90 MHz, CDCI₃): δ = 13.78, 18.48, 19.74, 37.88, 42.31 , 72.1 1 , 166.3 ppm.

TiCI₄ (8.05 g, 0.0420 mol) is added dropwise to THF (90ml) at 0⁰C to give a yellow pre- cipitate. A solution of 4-methoxybenzaldehyde (2.78 g, 0.02mol) and di-(1 -methylbutyl)- malonate (4.89g, 0.02mol) in THF (10 ml) is added slowly, followed by pyridine (25.3g,

0.32mol).

The reaction mixture is stirred at 0⁰C for 2h and then at room temperature overnight.

Water (60ml) and ethyl acetate (120ml) are added and stirring is continued until the solid material is dissolved.

The organic layer is separated, washed with brine, saturated aqueous NaHCO₃ solution and dried over Na₂SO₄.

The solvent is removed under reduced pressure using a rotary evaporator to yield 4- methoxybenzylidene-di-(1-methylbutyl)-malonate (7.17 g, 99%). The product may be further purified by Kugelrohr distillation under high vacuum. ¹H-NMR (360 MHz, CDCI₃): δ = 0.90 (t, J = 7.5 Hz, 3 H), 0.92 (t, J = 7.5 Hz, 3 H), 1.27 (t, J 5.5 Hz, 3 H), 1.28 (t, J = 5.5 Hz, 3 H), 1.30-1.55 (m, 6 H), 1.58-1.70 (m, 2 H), 3.82 (s, 3 H), 5.01-5.19 (m, 2 H), 6.87 (d, J = 9.0 Hz, 2 H), 7.44 (d, J = 9.0 Hz, 2 H), 7.62 (s, 1 H).

Example 14: 4-Methoxybenzylidene-di-isopropyl-malonate

To a solution of 4-methoxybenzaldehyde (16.7 g, 0.12 mol) and diisopropyl malonate (23.1 g, 0.12mol) is added Ti(OiPr)₄ (47.4 ml, 0.16 mol) and the resulting mixture is stirred at room temperature for 2 days. The resulting suspension is poured on ice-cold 1 M HCI (280 ml) and the mixture is stirred at 0⁰C for 30 min. Then the product is extracted with ethyl acetate and the organic layer is washed with sat. aq. NaHCO₃ and brine, then dried over Na₂SO₄. The solvent is removed under reduced pressure using a rotary evaporator. Purification by Kugelrohr distillation yields 4-methoxybenzylidene-diisopropylmalonate (33.1 g, 90%).

¹H-NMR (360 MHz, CDCI₃): δ = 1.29 (d, J = 6.5 Hz, 6 H), 1.31 (d, J = 6.5 Hz, 6 H), 3.82 (s, 3 H), 5.14 (sept, J = 6.5 Hz, 1 H), 5.26 (sept, J = 6.5 Hz, 1 H), 6.87 (d, J = 8.8 Hz, 2 H), 7.44 (d, J = 8.8 Hz, 2 H), 7.61 (s, 1 H) ppm.

Example 15: 4-Ethoxybenzylidene-di-isopropyl-malonate

This compound can be prepared by Knoevenagel condensation of diisopropyl malonate with 4-ethoxybenzaldehyde analogously to example 14. Example 16: 4-n-Propoxybenzylidene-di-isopropyl-malonate

This compound can be prepared by Knoevenagel condensation of diisopropyl malonate with 4-n-propoxybenzaldehyde analogously to example 14.

Example 17: 4-n-Butoxybenzylidene-di-isopropyl-malonate

This compound can be prepared by Knoevenagel condensation of diisopropyl malonate with 4-n-butoxybenzaldehyde analogously to example 14.

¹H-NMR (360 MHz, CDCI₃): δ = 0.97 (t, J = 7.5 Hz, 3 H), 1.30 (d, J = 6.0 Hz, 6 H), 1.31 (d, J = 6.0 Hz, 6 H), 1.43-1.54 (m, 2 H), 1.73-1.82 (m, 2 H), 3.98 (t, J = 6.5 Hz, 2 H), 5.14 (sept, J = 6.0 Hz, 1 H), 5.27 (sept., J = 6.0 Hz, 1 H), 6.86 (d, J = 9.0 Hz, 2 H), 7.42 (d, J = 9.0 Hz, 2 H), 7.61 (s, 1 H).

¹³C-NMR (90 MHz, CDCI₃): δ = 13.72, 19.12, 21.49, 21.74, 31.10, 67.75, 69.86, 68.96, 114.6, 124.2, 125.2, 131.5, 141.0, 161.1 , 164.0, 166.7 ppm.

Example 18: 4-Methoxybenzylidene-di-tert-butyl-malonate

(117)

A solution Of TiCI₄ (1.15ml, 10.5mmol) in CCI₄ (2.5ml) is added dropwise to THF (20ml) at 0⁰C to give a yellow precipitate.

A solution of 4-methoxybenzaldehyde (0.61 ml, δ.Ommol) and di-tert-butyl malonate (1.12ml, 5.0mmol) in THF is added slowly, followed by pyridine (6.75ml, 83.5mmol). The reaction mixture is stirred at 0⁰C for 2h and then at room temperature overnight. Water (30 ml) and ethyl acetate (30ml) are added and stirring is continued until the solid material is dissolved.

The organic layer is separated and washed with brine and saturated aqueous NaHCC>3 solution, dried over Na₂SO₄, and the solvent is removed under reduced pressure using a rotary evaporator.

The residue is then chromatographed on silica gel (cyclohexane/ethyl acetate 9:1 ) to yield 4- methoxybenzylidene-di-tert-butyl-malonate (1.32 g, 79%).

¹H-NMR (360 MHz, CDCI₃): δ = 1.53 (s, 9 H), 1.55 (s, 9 H), 3.83 (s, 3 H), 6.87 (d, J = 8.5 Hz, 2 H), 7.47 (d, J = 8.5 Hz, 2 H), 7.48 (s, 1 H) ppm.

¹³C-NMR (90 MHz, CDCI₃): δ = 27.89, 28.09, 55.27, 81.65, 82.04, 1 14.0, 125.9, 126.6, 131.4,

139.5, 161.2, 163.8, 166.4 ppm.

¹³C-NMR (90 MHz, CDCI₃): δ = 27.89, 28.09, 55.27, 81.65, 82.04, 114.0, 125.9, 126.6, 131.4,

139.5, 161.2, 163.8, 166.4 ppm.

Example 19: 4-Methoxybenzylidene-di-(1 ,1-dimethlpropyl)-malonate

Di-(1 , 1-dimethlpropyl)-malonate is prepared by base catalyzed transesterification of dimethyl malonate or diethyl malonate with 2-methyl-2-butanol as described in EP278914.

Alternatively, di-(1 ,1-dimethlpropyl)-malonate is prepared by reaction of malonyl dichloride with 2-methyl-2-butanol:

To a mixture of 2-methyl-2-butanol (55 ml, 0.50 mol) and N,N-dimethylaniline (41 ml, 0.32 mol) a solution of malonyl dichloride (14.0 g, 0.1 mol) in CHCI₃ (30 ml) is slowly added at 5°C. The reaction mixture is heated to 90⁰C for 4 h. Then the reaction mixture is cooled to room temperature and 6 N H₂SO₄ (75 ml) is slowly added. Then the product is extracted with three 125 ml portions of tert-butyl methyl ether. The combined ether extracts are washed once with 6 N H₂SO₄ , twice with water, twice with 10% aqueous K₂CO₃ solution, and once with brine, and are finally dried over Na₂SO₄ to which a small amount of K₂CO₃ is added. The solvent is removed under reduced pressure using a rotary evaporator. The residue is then distilled under reduced pressure (bp. 113-1 14°C/10 mbar) to yield di-(1 ,1-dimethylpropyl)- malonate (1 1.4 g, 47%).

¹H-NMR (360 MHz, CDCI₃): δ = 0.89 (t, J = 7.5 Hz, 6 H), 1.43 (s, 12 H), 1.77 (q, J = 7.5 Hz, 4 H), 3.19 (s, 2 H) ppm; ¹³C-NMR (90 MHz, CDCI₃): δ = 8.101 , 25.31 , 33.36, 44.28, 84.1 1 , 166.0 ppm. 1³C-NMR (90 MHz, CDCI₃): δ = 8.101 , 25.31 , 33.36, 44.28, 84.1 1 , 166.0 ppm.

The Knoevenagel condensation between di-(1 ,1-dimethlpropyl)-malonate and 4-methoxy- benzaldehyde is carried out analogously to example 17. 4-Methoxybenzylidene-di-(1 ,1- dimethlpropyl)-malonate is obtained in 87% yield after column chromatography.

¹H-NMR (360 MHz, CDCI₃): δ = 0.87 (t, J = 7.5 Hz, 3 H), 0.92 (t, J = 7.5 Hz, 3 H), 3.82 (s, 3 H), 6.86 (d, J = 8.8 Hz, 2 H), 7.47 (d, J = 8.8 Hz, 2 H), 7.49 (s, 1 H) ppm; ¹³C-NMR (90 MHz, CDCI₃): δ = 8.156, 8.209, 24.86, 25.61 , 33.28, 34.22, 55.26, 84.28, 84.66, 1 14.0, 125.9, 126.8, 131.4, 139.5, 161.1 , 163.8, 166.4 ppm.

¹³C-NMR (90 MHz, CDCI₃): δ = 8.156, 8.209, 24.86, 25.61 , 33.28, 34.22, 55.26, 84.28, 84.66, 114.0, 125.9, 126.8, 131.4, 139.5, 161.1 , 163.8, 166.4 ppm.

Application Example:

O/W sunscreen formulation containing 4-Methoxybenzylidene-di-tert-butyl-malonate (compound of example 18; formulation A)

Manufacturing instruction:

Prepare the part A and part B separately and heat to 75°C. Under increasing stirring, incorporate part B to part A and homogenize with Ultra Turrax for 10 sec. at lOOOOrpm. Let cool down to room temperature under stirring . At room temperature adjust pH between 5.80 and 6.20.

Testing of SPF:

The sample is applied on sand blasted PMMA plates (delivered by Helioscience, Marseille, France) with an application amount of 1 ,4 mg/cm², irradiated with an Atlas CPS+ solar simulator and tested in an Optometries SPF 290 analyzer. The calculation of the in vitro SPF is done according to B. L. Diffey and J. Robson, J. Soc. Cosmet. Chem. 1989, 40, 127-133. The in vitro SPF is determined to be 5.0.

Testing of photostability:

The photostability of Butyl 4-Methoxybenzylidene-di-tert-butyl-malonate is determined by spreading the emulsion as a 20μm thick film on four quartz plates. The plates are irradiated using a solar simulator for 1 h (5 MED), 2 h (10 MED), 4 h (20 MED) and 10 h (50 MED). After the indicated irradiation times one of the quartz plate is plunged into 5 ml of tetrahydro- furane. The amount of UV-B filter 4-Methoxybenzylidene-di-tert-butyl-malonate is then determined using high performance liquid chromatography. The residual 4-Methoxybenzyli- dene-di-tert-butyl-malonate is determined to be 100% (± 1 %) in all cases. Thus, 4-Methoxy- benzylidene-di-tert-butyl-malonate shows complete photostability in an O/W sunscreen formulation.

Testing of stabilization of Butyl Methoxydibenzoylmethane (BMDBM, Parsol 1789): O/W sunscreen formulation containing 4-Methoxybenzylidene-di-tert-butyl-malonate (compound of example 17) and Butyl Methoxydibenzoylmethane (formulation B)

The formulation is prepared as described above for formulation A.

The sample is applied on sand blasted PMMA plates (delivered by Helioscience, Marseille, France) with an application amount of 1 ,4 mg/cm², irradiated with an Atlas CPS+ solar simulator and tested in an Optometries SPF 290 analyzer. The calculation of the in vitro SPF is done according to B. L. Diffey and J. Robson, J. Soc. Cosmet. Chem. 1989, 40, 127-133. The in vitro SPF is determined to be 5.3.

The photostability of Butyl Methoxydibenzoylmethane is determined by spreading the emulsion as a 20μm thick film on a quartz plate. The film is irradiated using a solar simulator for 2 h (10 MED). After irradiation, the quartz plate is plunged into 5 ml of tetrahydrofurane. The amount of UV-A filter Butyl Methoxydibenzoylmethane is then determined using high performance liquid chromatography. The residual Butyl Methoxydibenzoylmethane is determined to be 47%.

O/W sunscreen formulation containing Butyl Methoxydibenzoylmethane (comparative formulation C)

The formulation is prepared as described above for formulation A.

The photostability of Butyl Methoxydibenzoylmethane in the comparative formulation C is determined as described above for formulation B. The residual Butyl Methoxydibenzoylmethane is determined to be 4%. Thus the recovery of Butyl Methoxydibenzoylmethane has been shown to be 11.75 times higher in the presence of 4-Methoxybenzylidene-di-tert-butyl- malonate (compound of example 17).

Claims

1. Use of benzylidene malonates of formula

(1 ) , wherein

R₁ is methyl; ethyl; propyl; or n-butyl; if R₁ is methyl, then

R is tert. butyl; ; a radical of formula

(1 a) ; wherein

R₂ and R₃, independently from each other are hydrogen; or methyl;

R₄ is methyl; ethyl; or n-propyl;

2. Use according to claim 1 , which comprises the compounds of formula

(1 ), wherein

R₁ is methyl; ethyl; propyl; or n-butyl; if R₁ is methyl, then

R is tert. butyl; ; a radical of formula (1a) ; or a

radical of forumula (1 b)

R₅ and R₆ independently from each other are hydrogen; or d-C₃alkyl; if R₁ is ethyl; propyl; or n-butyl, then

R is isopropyl.

3. Use according to claim 1 or 2, wherein

R is a radical of formula

Ri is methyl.

4. Use according to any of claims 1 to 3, wherein in formula (1 a) at least one of R₂ or R₃ is methyl.

5. Use according to any of claims 1 to 4, wherein in formula (1a) R₂ and R₃ are methyl.

6. Use according to claim 1 , wherein Ri is ethyl; propyl; or n-butyl; and R is isopropyl.

7. Cosmetic preparation comprising at least one or more compounds of formula (1 ) according to claim 1 together with cosmetically tolerable carriers or adjuvants.

8. A preparation according to claim 7 that comprises further UV protective agents.

9. A preparation according to claim 8, wherein the UV protecting agents are selected from p- aminobenzoic acid derivatives, salicylic acid derivatives, benzophenone derivatives, dibenzo- ylmethane derivatives, diphenylacrylates, 3-imidazol-4-yl acrylic acid and esters; benzofuran derivatives, polymeric UV absorbers, cinnamic acid derivatives, camphor derivatives, hydro- xyphenyltriazine compounds, benzotriazole compounds, trianilino-s-triazine derivatives, 2- phenylbenzimidazole-5-sulfonic acid and salts thereof; menthyl o-aminobenzoate; merocy- anine derivatives; encapsulated UV absorbers, 4,4-diphenyl-1 ,3-butadiene derivatives, tris- (aryl) triazines, TiC>2, ZnO and mica.

10. Use of benzylidene malonates as defined in claim 1 in a cosmetic formulation for the stabilization of other UV filters.

1 1. Benzylidene malonates corresponding to formula

(V) , wherein

R'-i is methyl; ethyl; propyl; or n-butyl; if R'-i is methyl, then

R' is tert. butyl; or a radical of formula (1 'a) ; or a

radical of forumula (1 'b) * — ( / ; wherein

R'₂ and R'₃, independently from each other are hydrogen; or methyl; R ₄ is methyl; ethyl; or n-propyl; if R^ is ethyl; or propyl; then R' is isopropyl.

12. Benzylidene malonates according to claim 11 , wherein R'i is methyl.

13. Benzylidene malonates according to claim 12, wherein R'₂ and R'3 are methyl.

14. Benzylidene malonates according to claim 12 or 13, wherein

R' is a radical of formula

R^ is methyl.

15. Benzylidene malonates according to claim 11 , wherein R'i is ethyl; propyl; or n-butyl; and R' is isopropyl.