(3,5-diaminophenyl)(2,4-dihydroxyphenyl)methanone and the acid adducts thereof, method for their preparation and use of these compounds for dyeing fibers

1. (3,5-Diaminophenyl)(2,4-dihydroxyphenyl)methanone and the acid adducts thereof of formula (I), with 0≦n≧2 and HX denoting an inorganic or organic acid.

2. Compound as defined in claim 1 , characterized in that the HX acid is selected from among hydrochloric acid, sulfuric acid, phosphoric acid, citric acid and tartaric acid.

3. Ready-to-use agent for oxidative coloring of keratin fibers which is prepared by mixing a dye carrier composition with an oxidant just before use and is characterized in that the dye carrier composition contains at least one compound of formula (I) as defined in claim 1 .

4. Agent as defined in claim 3 , characterized in that it contains the compound of formula (I) in an amount from 0.01 to 10 weight percent (based on the dye carrier composition).

5. Agent as defined in claim 3 , characterized in that it contains at least one developer.

6. Agent as defined in claim 3 , characterized in that additionally it contains other developers and/or couplers and/or direct dyes.

7. Agent as defined in claim 5 , characterized in that the total amount of developers and couplers is 0.01 to 10 weight percent (based on the dye carrier composition).

8. Agent as defined in claim 6 , characterized in that the total amount of direct dyes is from 0.1 to 10 weight percent (based on the dye carrier composition).

9. Agent as defined in claim 3 , characterized in that it is a hair colorant.

10. Method for preparing the compounds of formula (I) as defined in claim 1 whereby first 3,5-dinitrobenzoyl chloride is made to react with resorcinol under Friedel-Crafts conditions and the resulting product is then catalytically hydrogenated to give the end product of formula (I) which finally is isolated either as the free base or as the acid adduct.