- Compounds derived from diaminopyrazoles substituted by an aminoalkyl or aminoalkenyl radical and their use in oxidation dyeing of keratinous fibres
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The invention concerns compounds derived from diaminopyrazole of formula (I), wherein: R1 is a linear or branched radical selected among C2, C3, C4 aminoalkyl radicals or C2, C3, C4 aminoalkenyl radicals, or one of the physiologically acceptable salts thereof. The invention also concerns compositions containing said compound for dyeing keratinous fibres and the method using said compositions.
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- Diaminopyrazole derivatives and their use for oxidation dyeing of keratinous fibres
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The invention relates to diaminopyrazole derivatives having the following structure (I), wherein R1 represents an alkyl or alkenyl radical bearing at least one substituent selected from among OR, NRR′, SR, SOR, SO2R, COOR, CONRR′, PO(OH)2, SO3X, NHCONRR, a non-cationic heterocycle, an aryl, a halogen. R2 and R3 are different from H and represent, independently of each other, an alkyl or alkenyl group; R2 and R3, together with the nitrogen atom to which they are attached, can form a heterocycle possibly comprising at least one other heteroatom selected from among N, O and S; R2 and R3 or the heterocycle that they form with the nitrogen to which they are attached can be substituted by at least one substituent defined above. The identical or different R, R′ groups are selected from a hydrogen atom, an alkyl or alkenyl group; R and R′, together with the nitrogen atom to which they are attached, can form a heterocycle having at least 4 ring members that can contain at least one additional heteroatom selected from among O, N and S. X represents a hydrogen, an alkaline-earth or alkali metal atom or an ammonium group. The invention also relates to the dyeing compositions and the dyeing methods using same.
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- Diaminopyrazole compounds and the use thereof in the oxidation dyeing of keratinous fibres
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The invention relates to novel diaminopyrazole having formula (I), wherein: R1, R2, identical or different, represent a C3 C5 mono- or polyhydroxyalkyl, isopropyl, n-propyl or ethyl group, said groups being linear or branched, and their physiologically acceptable salts. The invention also relates to a composition for dyeing keratinous fibres containing a compound having formula (I) and the method for using same. 1
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- Diaminopyrazole compounds and the use thereof in the oxidation dyeing of keratinous fibres
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The invention relates to novel diaminopyrazole compounds having formula (I): wherein R1 represents a linear or branched C4-C5 alkyl or n-propyl group, or a linear or branched C3-C5 mono or polyhydroxy alkyl group, and the addition salts thereof with a physiologically acceptable acid. The invention also relates to the compositions containing such a compound for the dyeing of keratinous fibers and the method for using said compositions.
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- Selective Thermolysis Reactions of Bromo-1-nitro-1H-pyrazoles. Formation of 3-Nitro-1H-vs. 4-Nitro-1H-pyrazoles
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Refluxing 3,4,5,-tribromo-1-nitro-1H-pyrazole (1a) in benzene results in the evolution of bromine and NO2 and gives the 4-nitro-1H-pyrazole 2 and the 1-phenyl-1H-pyrazoles 4 and 5, while heating 1a in toluene gives 2 and benzyl bromide.Thermolysis of 1a in refluxing acetonitrile affords both 2 and the isomeric 5-nitro-1H-pyrazole 6a.Refluxing 1a mixed with the electron-rich 3,5-dimethyl-1H-pyrazole (7) in all three solvents gives 6a and 4-bromo-3,5-dimethyl-1H-pyrazole (8), whereas refluxing 1a mixed with anisole in benzene solution gives 2 and bromoanisoles.3,5-Dibromo-1-nitro-1H-pyrazole (1b) in refluxing acetonitrile gives mainly 3,4-dibromo-5-nitro-1H-pyrazole (6a) and 3,5-dibromo-1H-pyrazole (3b), but refluxing 1b mixed with 7 affords 3-bromo-5-nitro-1H-pyrazole (6b).Possible mechanisms are discussed involving intramolecular rearrangements to intermediates 3-bromo-3-nitro-3H-pyrazoles 9a,b and 4-bromo-4-nitro-4H-pyrazole 10 responsible both for the loss of bromine and NO2 as well as for the electrophilic bromination of 7 and anisole.
- Juffermans, J. P. H.,Habraken, Clarisse L.
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p. 4656 - 4660
(2007/10/02)
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