Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
1999-12-09
2001-07-10
Trinh, Ba K. (Department: 1625)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C549S323000, C424S059000, C424S060000
Reexamination Certificate
active
06258963
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to modified benzylidene-&ggr;-butyrolactones, to a process for their preparation and to the use as UV absorber, for example in pharmaceutical and cosmetic compositions, sunscreens, daycare and haircare products, for improving industrial products, such as paints, surface coatings, plastics, textiles, packaging materials and rubbers.
BACKGROUND OF THE INVENTION
Depending on their wavelength, UV rays are divided in UV-A rays (320-400 nm) and UV-B rays (280-320 nm). The harmful effect, in particular the occurrence of sunburn (erythema), increases not only with the duration of exposure but also with decreasing wavelength and is thus significantly more strongly marked in the case of UV-B radiation than in the case of UV-A radiation. Since erythemas can occur even after short exposure to the sun, in some cases after 20-30 minutes, efficient protection against this radiation is of particular importance.
For this area of UV protection, a number of UV-B absorbers are already known from the prior art. Examples mentioned are camphor derivatives, salicylic acid derivatives, benzophenones, cinnamates, benzimidazoles and triazines. One example of benzylidene-&ggr;-butyrolactones is described in European Patent Application EP-A 44970. These are compounds of the formula
in which
R is a C
1
-C
15
-alkyl radical, branched or unbranched, phenyl or benzyl.
However, all of these compounds have the disadvantages that they are either in the form of a solid and thus have only limited solubility in the cosmetic preparations, exhibit only low absorption or have photostability which does not meet the necessary criteria and are thus unsatisfactory.
SUMMARY OF THE INVENTION
Accordingly, the object of the present invention is to provide improved UV-B absorbers. This object is achieved by benzylidene-&ggr;-butyrolactones of the general formula
wherein
R is hydrogen or C
1
-C
6
-alkyl or cycloalkyl, and
R
1
to R
5
independently of one another are hydrogen, but at most 4, are hydrogen at the same time, or C
1
-C
8
-alkyl or cycloalkyl, and also R
1
/R
2
and/or R
3
/R
4
can form a carbocyclic ring having from 5 to 7 ring atoms.
According to the present invention, particular preference is given to benzylidene-&ggr;-butyrolactones in which the lactone ring is trisubstituted at R
1
, R
3
and R
4
by an alkyl, where an alkyl group includes at least one C
2
chain. Likewise preferred are benzylidene-&ggr;-butyrolactones whose benzylidene ring is substituted in the para-position by a methoxy radical, and R
1
is an ethyl radical, R
2
is hydrogen, and R
3
/R
4
is a methyl radical.
Specific benzylidene-&ggr;-butyrolactones compounds of the present invention include: p-Methoxybenzylidene-4-methyl-&ggr;-butyrolactone, p-methoxybenzylidene-4-butyl-&ggr;-butyrolactone, p-methoxybenzylidene-4,4-dimethyl-&ggr;-butyrolactone, p-methoxy-benzylidene-3,4-dimethyl-&ggr;-butyrolactone, p-methoxybenzylidene-3,4,4-trimethyl-&ggr;-butyrolactone, p-methoxybenzylidene-3-methyl-4-pentyl-&ggr;-butyrolactone, p-methoxybenzyl-idene-3-methyl-4-hexyl-&ggr;-butyrolactone, o,p-dimethoxybenzylidene-4-butyl-&ggr;-butyrolactone, o,p-dimethoxybenzylidene-4,4-dimethyl-&ggr;-butyrolactone, o,p-dimethoxybenzylidene-3,4-dimethyl-&ggr;-butyrolactone, m,p-dimethoxybenzylidene-4-butyl-&ggr;-butyrolactone, m,p-dimethoxybenzyl-idene-4,4-dimethyl-&ggr;-butyrolactone, m,p-dimethoxybenzylidene-3,4-dimethyl-&ggr;-butyrolactone, p-methoxybenzylidene-3-ethyl-4,4-dimethyl-&ggr;-butyrolactone, p-methoxybenzylidene-3,4-dimethyl-4-butyl-&ggr;-butyro-lactone, p-methoxybenzylidene-3,4-dimethyl-4-ethyl-&ggr;-butyrolactone. Particularly preferred benzylidene-&ggr;-butyrolactones include p-methoxy-benzylidene-3-ethyl-4,4-dimethyl-&ggr;-butyrolactone, p-methoxybenzylidene-3,4-dimethyl-4-butyl-&ggr;-butyrolactone, p-methoxybenzylidene-3,4-dimethyl-4-ethyl-&ggr;-butyrolactone.
The benzylidene-&ggr;-butyrolactones according to the present invention can be prepared in accordance with the prior art by aldol condensation of substituted benzaldehydes, for example anisaldehyde, with correspondingly substituted &ggr;-butyrolactones, for example &bgr;-ethyl-&ggr;,&ggr;-dimethyl-&ggr;-butyrolactone.
Additionally, the benzylidene-&ggr;-butyrolactones according to the present invention are particularly suitable as UV absorbers and solvents for solid UV absorbers, which have relatively poor solubility within a pharmaceutical or cosmetic preparation. Accordingly, the present invention also provides compositions which comprise the above-mentioned benzylidene-&ggr;-butyrolactones and are suitable for protecting against harmful UV radiation. In this connection, the compositions according to the present invention can comprise one or more of the benzylidene-&ggr;-butyrolactones according to the invention.
Preference is given to compositions which comprise from 0.1 to 15% by weight of benzylidene-&ggr;-butyrolactones according to the present invention, based on the total weight of the preparation. Particular preference is given to compositions comprising from 1 to 10% by weight, and most preferably comprising from 2 to 7% by weight, of benzylidene-&ggr;butyrolactone according to the present invention.
According to the present invention, the above-mentioned compositions are preferably suitable as sunscreens or daycare products for protecting human skin and hair, in particular hair already predamaged by permanent waving, coloring and bleaching, against harmful UV radiation.
According to the present invention, the compositions can also be mixed with additives known per se and/or known UV absorbers of other classes of substance and/or known pigments.
Examples of common additives are emulsifiers, surface-active compounds, lanolin, petroleum jelly, water, triglycerides of fatty acids, polyethylene glycols, fatty alcohols, ethoxylated fatty alcohols, fatty acid ester such as, for example, isopropyl palmitate, isooctyl sterate, diisopropyl adipate etc., natural or synthetic oils or waxes, thickeners, such as, for example, hydroxyethylcellulose, bentonite, etc., preservatives, moisturizers, vitamins, skin-lightening active ingredients such as, for example, hydroquinones, arbutin, kojic acid and derivatives, ascorbic acid and derivatives, glutathione, hydroxybenzaldoximes, e.g., 4-hydroxy-3-methoxybenzaldehyde oxime, antioxidants such as, for example, BHT, vitamin derivatives, catechol derivatives, e.g., epigallocatechol gallate or 3,4-dihydroxybenzaldehyde oxime, complexing agents such as, for example, EDTA and derivatives, insect repellents such as, for example, DEET or IR 3535, silicone oils, glycerol, ethyl alcohol and perfume oils. The list of additives is not limited to the examples given. Pigments which can be added are, for example, titanium dioxide, zinc oxide, pearlizing pigments or color pigments.
Examples of traditional UV absorbers include p-aminobenzoic acid, ethyl p-amino-benzoate (25 mol) ethoxylated, 2-ethylhexyl p-dimethyl-aminobenzoate, ethyl p-aminobenzoate (2 mol) N-propoxylated, glycerol p-aminobenzoate, homomenthyl salicylate, 2-ethylhexyl salicylate, triethanolamine salicylate, 4-isopropylbenzyl salicylate, methyl anthranilate, ethyl diisopropylcinnamate, 2-ethylhexyl p-methoxy-cinnamate, methyl diisopropylcinnamate, isoamyl p-methoxycinnamate, p-methoxy-cinnamic acid diethanolamine salt, isopropyl p-methoxycin-namate, 2-ethylhexyl 2-cyano-3,3-diphenyl acrylate, ethyl 2-cyano-3,3′-diphenyl acrylate, 2-phenyl-benzimidazolesulphonic acid and salts, 3-(4′-trimethylammonium)-benzylidene-bornan-2-one methylsulphate, terephthalylidene-dibornanesulphonic acid and salts, 4-t-butyl-4′-methoxydibenzoylmethane, &bgr;-imidazole-4(5)-acrylic acid (urocanic acid). 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulphonic acid, dihydroxy-4-methoxybenzophenone, 2,4-dihydroxy-benzophenone, tetrahydroxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-methoxy-4′-methylbenzophenone, 3-(4′sulpho)benzylidene-bornan-2-one and salts, 3
Johncock William
Koch Oskar
Langner Roland
Cheung Noland J.
Gil Joseph C.
Haarmann & Reimer GmbH
Trinh Ba K.
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