3,4-Dihydroxymandelic acid alkylamides and use thereof
OwnerJakob Peter Leyinventor
Life of this patent
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Abstract
The invention relates to N-alkyl-2-(3,4-dihydroxyphenyl)-2-hydroxyacetamides and to cosmetic and/or pharmaceutical preparations and foods comprising these compounds.
Claims17
A 3,4-dihydroxymandelic acid alkylamide of the general formula
- 6
- where
- R1, R2 and R3, independently of one another, are hydrogen, lower alkyl or groups —O—R6 in which R6 is hydrogen or lower alkyl, and
- R4 is hydrogen, an alkyl radical having 1 to 22 carbon atoms or an alkenyl radical having 2 to 22 carbon atoms, and
- R5 is an alkyl radical having 1 to 22 carbon atoms or an alkenyl radical having 2 to 22 carbon atoms,
- including a stereoisomer thereof or mixture thereof.
A 3,4-dihydroxymandelic acid alkylamide of the formula
- 7
- where
- R1, R2and R3, independently of one another, are hydrogen, methyl, tert-butyl, hydroxyl or methoxy, and
- R4 is hydrogen, and
- R5 is an alkyl radical having 1 to 18 carbon atoms or an alkenyl radical having 2 to 20 carbon atoms,
- including a stereoisomer thereof or mixture thereof.
A 3,4-dihydroxymandelic acid alkylamide of the formula
- 8
- where
- R1, R2, R3 and R4 are hydrogen, and
- R5 is an alkyl radical having 1 to 12 carbon atoms or an alkenyl radical having 2 to 12 carbon atoms,
- including a stereoisomer thereof or mixture thereof.
2-(3,4-Dihydroxyphenyl)-N-n-hexyl-2-hydroxyacetamide, N-cyclohexyl-2-(3,4-dihydroxyphenyl)-2-hydroxyacetamide and 2-(3,4-dihydroxyphenyl)-N-(2-ethylhexyl)-2-hydroxyacetamide.
A process for the preparation of the 3,4-dihydroxymandelic acid alkylamides of the formula
- 9
- where
- R1, R2 and R3, independently of one another, are hydrogen, lower alkyl or groups —O—R6 in which R6 is hydrogen or lower alkyl, and
- R4 is hydrogen, an alkyl radical having 1 to 22 carbon atoms or an alkenyl radical having 2 to 22 carbon atoms, and
- R5 is an alkyl radical having 1 to 22 carbon atoms or an alkenyl radical having 2 to 22 carbon atoms,
- including stereoisomers thereof or mixtures thereof,
- characterized in that, a 3,4-dihydroxymandelic acid activated in the form of the acid chloride, the acid anhydride or an acid ester, for example of optionally substituted phenols, N-hydroxysuccinimide or N-hydroxybenzotriazole and optionally protected on the phenolic OH groups is reacted with an alkylamine of the general formula HNR4R5 or an ammonium salt of the general formula (H2NR4R5)+A−, where the radicals R4 and R5 have the meanings given above and A− is an inorganic or organic anion, for example halide, sulfate, hydrogensulfate or acetate, optionally in the presence of solvents and auxiliary bases, and any protective group which may be present are cleaved off.
A process for the preparation of the 3,4-dihydroxymandelic acid alkylamides of the formula
- 10
- where
- R1, R2 and R3, independently of one another, are hydrogen, lower alkyl or groups —O—R6 in which R6 is hydrogen or lower alkyl, and
- R4 is hydrogen, an alkyl radical having 1 to 22 carbon atoms or an alkenyl radical having 2 to 22 carbon atoms, and
- R5 is an alkyl radical having 1 to 22 carbon atoms or an alkenyl radical having 2 to 22 carbon atoms,
- including stereoisomers thereof or mixtures thereof, characterized in that
- the free 3,4-dihydroxymandelic acids are condensed directly with an alkylamine of the general formula HNR4R5, where the radicals R4 and R5 have the meanings given above, with or without solvents with the elimination of water with the aid of a condensing agent, preferably N,N′-dicyclohexylcarbodiimide.
Dependencies are inferred from the claim text.