Abstract: A hair dye composition comprising a primary intermediate, a coupler and oxidant and water wherein the primary intermediate is a compound of the formula I or II with the proviso that when the primary intermediate has the formula II, the coupler has the formula III

Abstract: Oxidative hair dyeing systems are provided that are “root seeking”, i.e., which produce more intense initial coloration on new growth, less porous hair compared to the initial coloration produced in older, damaged, more porous hair. More equalized coloration along the shaft of hair can be obtained with the “root seeking” dyeing products.

Abstract: 5-Nitroisatin is reacted with sodium hydroxide to produce an &agr;-keto acid sodium salt that is reduced with borane-tetrahydrofuran complex and then hydrogenated to produce 1-(2,5-diaminophenyl)ethylene glycol, a novel compound useful as a primary intermediate in the production of oxidative hair dyes.

Abstract: The novel primary intermediate, 1-(5-amino-2-hydroxyphenyl)ethane-1,2-diol and a method for producing same, are disclosed. The novel intermediate can be employed as a replacement for p-aminophenol in oxidation dye formulations.

Abstract: The invention provides compositions and methods for the oxidative coloring of human hair. The compositions of the invention contain as a primary dye intermediate a 1-(4-aminophenyl) pyrrolidine, or a cosmetically acceptable salt thereof. The compositions may also contain at least one other primary intermediate and conventional coupling compounds, in addition to an oxidizing agent and other components typically used in oxidative hair dye preparations. Preferred dye intermediates in the compositions of the invention include 1-(4-aminophenyl) pyrrolidine and 1-(4-amino-3-methylphenyl) pyrrolidine, or cosmetically acceptable salts thereof, which produce intense neutral colors when used in admixture with a suitable coupling agents, such as 3-aminophenol, in conventional hair dye base formulations.