- Coupling compounds and hair dyeing compositions containing them
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The present invention refers to compounds of the formula (I) wherein R1 is (C1-C4)-alkyl, (C1-C4)-alkyl which is substituted by hydroxy, (C1-C4)-alkoxy, hydroxy-(C1-C4)-alkoxy, CN, -COOR5, -CON(R5)2 or -N(R5)2 or is phenyl; R2 is hydrogen, methyl or ethyl; R3 is (C1-C4)-alkylsulfonyl, (C1-C4)-alkylsulfonyl which is substituted by hydroxy, halogen, cyano, (C1-C4)-alkoxy or -N(R5)2 or is -SO2-CH=CH2, -SO2N(R5)2 or -PO(OR5)2; R4 is hydrogen, (C2-C4)-alkyl which is substituted by hydroxy, (C1-C4)-alkoxy or hydroxy-(C1-C4)-alkoxy; each of R5, independently is hydrogen, (C1-C4)-alkyl or hydroxy-(C2-C4)-alkyl; whereas R3 is not -NHSO2CH3 if R2 and R4 are both hydrogen and R1 is methyl, as well as hair dye compostions containing them.
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Page/Page column 9
(2008/06/13)
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- PARTIAL REDUCTION OF DINITROARENES TO NITROANILINES WITH HYDRAZINE HYDRATE.
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Dinitroarenes containing substituents such as hydroxyl and amine groups could be conveniently reduced with 3 molar equivalents of hydrazine hydrate in presence of Raney nickel catalyst in ethanol/1,2-dichloro-ethane solvent mixture to give a product wherein one of the two nitro groups was reduced to the amino group. The yields of the partial reduction products are good. Under similar conditions alkoxyl substitutes in the o,p-position to the nitro groups were displaced by the hydrazine to give 2,4-dinitrophenyl-hydrazine as the main product. The details of the reduction reaction are described.
- Avyyangar,Kalkote,Lugade,Nikrad,Sharma
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p. 3159 - 3164
(2007/10/02)
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