Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
2002-06-18
2004-01-20
McKane, Joseph K. (Department: 1616)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C558S401000
Reexamination Certificate
active
06680390
ABSTRACT:
The invention relates to the use of vinyl-substituted tetrahydronaphthalenes or benzotetrahydropyrans which carry electron-withdrawing substituents on the vinyl radical, as light protection agents in cosmetic and pharmaceutical preparations and as light protection additives in plastics. The invention further relates to novel compounds of said type which have a light protection action and which carry cyano groups as electron-withdrawing substituents.
The light protection agents used in cosmetic and pharmaceutical preparations have the task of preventing, or at least diminishing the consequences of, harmful effects of sunlight on the human skin. However, these light protection agents also serve to protect other ingredients from decomposition or breakdown by UV radiation. In hair cosmetic formulations the aim is to reduce damage to the keratin fibers by UV rays.
The sunlight reaching the surface of the earth contains UV-B radiation (280 to 320 nm) and UV-A radiation (>320 nm), which are directly adjacent to the visible light region. The effect on the human skin is manifested, particularly in the case of UV-B radiation, by sunburn. Accordingly, the industry offers a relatively large number of substances which absorb UV-B radiation and thus prevent sunburn.
Dermatological investigations have now shown that UV-A radiation is also perfectly capable of causing skin damage and allergies by, for example, damaging the keratin or elastin. This reduces the elasticity and water storage capacity of the skin, i.e. the skin becomes less supple and tends to form wrinkles. The noticeably high incidence of skin cancers in areas of strong solar radiation shows that damage to the genetic information in the cells is evidently also caused by sunlight, specifically by UV-A radiation. All these findings would therefore suggest that it is necessary to develop efficient filter substances for the UV-A region.
There is a growing demand for light protection agents for cosmetic and pharmaceutical preparations which can be used in particular as UV-A filters and whose absorption maxima ought therefore to be in the range from about 320 to 380 nm. In order to achieve the desired effect using the minimum amount, light protection agents of this type should additionally have a high specific absorbance. Light protection agents for cosmetic preparations must also meet a large number of other requirements, for example good solubility in cosmetic oils, high stability of the emulsions prepared therewith, toxicological acceptability and low intrinsic odor and low intrinsic color.
Another requirement which light protection agents must meet is adequate photostability. However, this is only inadequately ensured, if at all, with the UV-A-absorbing light protection agents available hitherto.
French Patent No. 2 440 933 describes 4-(1,1-dimethylethyl)-4′-methoxydibenzoylmethane as a UV-A filter. It is proposed to combine this particular UV-A filter, which is sold by GIVAUDAN under the name “PARSOL 1789”, with various UV-B-filters in order to absorb all UV rays having a wavelength from 280 to 380 nm.
However, this UV-A filter does not have sufficient photochemical stability, when used alone or in combination with UV-B filters, to ensure sustained protection of the skin during sunbathing for extended periods, which means that repeated applications at regular and short intervals are required if effective protection of the skin from all UV rays is desired.
For this reason, EP-A-0 514 491 discloses the stabilization of the insufficiently photostable UV-A filters by adding 2-cyano-3,3-diphenylacrylic esters, which themselves act as filters in the UV-B region.
Furthermore, it has already been proposed in EP-A-0 251 398 to combine chromophores which absorb UV-A radiation and UV-B radiation into a molecule via a linker. This has the disadvantage that firstly it is no longer possible to freely combine UV-A and UV-B filters in the cosmetic preparation, and that difficulties in the chemical linkage of the chromophores permit only certain combinations.
U.S. Pat. No. 4,950,467 describes the use of 2,4-pentadienoic acid derivatives as UV absorbers in cosmetic preparations. The monoaryl-substituted compounds specified in this patent specification as being preferable likewise have the disadvantage that their photostability is insufficient.
It is an object of the present invention to propose light protection agents for cosmetic and pharmaceutical purposes which absorb predominantly in the UV-A region (and optionally alternatively in the UV-B region) with high absorbance, are photostable, have low intrinsic color, i.e. a sharp band structure, and are soluble in oil or water depending on the substituent.
We have found that this object is achieved according to the invention by the use of compounds of the formula I
in which
X is the divalent radical of oxygen, a carbonyl radical, optionally aliphatically substituted imino or the radical ═CR
9
R
10
,
Y is a carbonyl group or the radical ═CR
9
R
10
,
R
1
and R
2
are identical or different electron-withdrawing radicals, chosen from the group consisting of cyano, alkyl- or arylcarbonyl, alkyloxy- or aryloxycarbonyl, optionally substituted aminocarbonyl, alkyl- or arylsulfinyl, alkyl- or arylsulfonyl and optionally substituted aminosulfonyl,
R
3
is a hydrogen atom, a cyano, hydroxyl, carboxyl or aminocarbonyl group or a C
5
-C
20
-aryl radical or C
1
-C
20
-alkyl radical optionally bonded via an oxygen bridge, an aminocarbonyl bridge or oxycarbonyl bridge,
R
4
is a hydrogen atom, a hydroxyl group, an amino group, or a C
5
-C
20
-aryl radical or C
1
-C
20
-alkyl radical optionally bonded via an oxygen bridge, and
R
5
to R
10
independently of one another are hydrogen or C
1
-C
20
-alkyl radicals and where in addition R
7
and R
8
together with the chain carbon atom are a carbonyl group,
as photostable UV filters in cosmetic and pharmaceutical preparations for protecting human skin and human hair from solar rays, alone or together with compounds which absorb in the UV region and are known per se for cosmetic and pharmaceutical preparations.
The alkyl radicals in the substituents R
1
and/or R
2
generally have from 1 to 20 carbon atoms and are preferably low molecular weight alkyl radicals having from 1 to 8 carbon atoms and are, in particular, methyl radicals.
The aryl radicals in the substituents R
1
and/or R
2
are isocyclic or heterocyclic radicals having from 5 to 10 ring atoms and from 3 to 20 carbon atoms, such as phenyl, naphthyl, pyridyl, thiazinyl or furanyl, which can be further substituted.
Alkyl radicals for R
3
and R
4
and R
5
to R
10
are preferably low molecular weight radicals having from 1 to 5 carbon atoms, preferably methyl. R
3
and/or R
4
as aryl radical is generally a mono- or binuclear isocyclic or heterocyclic radical, which can also be further substituted. Examples are phenyl, naphthyl, pyridyl, thiazinyl or furanyl.
Of the compounds of the formula I, preference is given to those in which R
3
to R
8
are hydrogen and X and Y are ═CR
9
R
10
, where R
9
and R
10
are hydrogen or low molecular weight alkyl radicals having from 1 to 5 carbon atoms or
R
3
to R
8
are hydrogen and X is oxygen and Y is ═CR
9
R
10
, where R
9
and R
10
are hydrogen or alkyl radicals having from 1 to 5 carbon atoms.
Particular preference is given to compounds of the formula I in which R
1
and/or R
2
are the radicals ethoxycarbonyl, acetyl or cyano, R
3
is hydrogen or methyl-, R
4
is hydrogen or methyl-, R
5
to R
8
are hydrogen, X is oxygen or ═C(CH
3
)
2
and Y is ═CH
2
or ═C(CH
3
)
2
.
Of the compounds of the formula I, compounds of the formula II
in which
R
3
is a low molecular weight alkyl radical,
R
4
is hydrogen, a low molecular weight alkyl radical or a low molecular weight alkoxy radical,
X is the divalent radical of oxygen or the radical ═CRR, where R is hydrogen or low molecular weight alkyl, are novel and are therefore claimed as new substances.
The compounds of the formula I or II are obtained in a manner known per se b
Habeck Thorsten
Prechtl Frank
Westenfelder Horst
Wilnsch Thomas
BASF - Aktiengesellschaft
Keil & Weinkauf
McKane Joseph K.
Saeed Kamal
LandOfFree
Use of substituted vinyl-tetrahydronaphthalenes and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Use of substituted vinyl-tetrahydronaphthalenes and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Use of substituted vinyl-tetrahydronaphthalenes and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3223816