HAIR COLORING WITH OXIDATION DYE INTERMEDIATES 613 Table III Para-Aminophenol Derivatives Color Compound Patent on Hair a Depth of Shade Solubility Fades (Darkest at pH 9.7 After to (g/100 (in Lightest) ml) hours) p-Aminophenol 4-Amino-2-methyl phenol sulfate 4-Amino-3-methyl phenol 4-Amino-2-nitro phenol 2,4-Diaminophenol hydrochloride (areidol) p-Methylamino phenol sulfate (metol) G.P. 51,073 Golden brown G.P. 80,814 Red brown G.P. 80,814 Light grey brown U.S.P. 1,466,747 Red brown G.P. 80,814 Light red brown G.P. 80,814 No color 2 0.63 12 1 1.17 14 5 0.43 10 3 2.97 10 4 7.46 2 6 5.58 Derivative used at a concentration of 0.025 moles/1. Table IV Ortho-Aminophenol Derivatives Color on Compound Patent Hair a Depth of Shade Solubility Fades (Darkest at pH 9.7 After to (g/100 (in Lightest) ml) hours) o-Aminophenol G.P. 103,505 Golden orange 4-Chloro-2-amino G.P. 103,505 Grey yellow phenol 4-Nitro-2-amino G.P. 103,505 Golden brown phenol 5-Nitro-2-amino U.S.P. 1,416,646 Bright yellow phenol 4,6-dinitro-2-amino- G.P. 103,505 Dark orange phenol 6-Chloro-4-nitro-2- ... Dark orange aminophenol hydrochloride 3 0.95 2 5 1.19 10 6 3.47 10 4 0.99 4 1 0.1325øc' 12 2 1.49 28 Derivative used at a concentration of 0.025 moles/1.

614 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table V Diphenylamine Derivatives Compound Patent Color on Hair • Depth of Shade Solubility Fad es (Darkest at pH 9.7 After to (g/100 (in Lightest) ml) hours) 4-Aminodiphenylamine G.P. 92,006 2,4-Diaminodiphenyl B.P. 270,075 amine 4,4'-Diaminodiphenyl- G.P. 98,431 amine sulfate 2-Aminodiphenylamine G.P. 162,625 3-Methyl-4-amino-4'- G.P. 209,121 hydroxydiphenyl- amine 4-Methoxy-4'-amino- G.P. 257,763 diphenylamine sulfate 4-Hydroxydiphenyl- G.P. 162,625 amine 3-Hydroxydiphenyl- G.P. 286,337 amine Brown black 1 0.10 15 Brown 3 0.15 7 Red brown 2 0.65 10 Grey red 4 0.07 6 Very little color 6 0.09 2 Light ash 5 1.06 4 No color 8 0.15 No color 7 0.16 Derivative used a concentration of 0.005 moles/1. tained under the conditions used in these dyeins experiments. It seemed possible that the reason that 2,4-diaminophenol hydrochloride did not produce a darker color than p-aminophenol might be due to oxi- dative destruction of the molecule because of the high concentration of hydrosen peroxide used in the dyeing. In order to check this the dye- inss of these two intermediates were repeated with the hydrosen peroxide concentration reduced from 3.0% to 0.3%. Under these conditions the color produced by p-aminophenol matched that of the original dye- in s but that produced by 2,4-diaminophenol hydrochloride was many times darker and redder than the original color. It can therefore be concluded that 2,4-diaminophenol hydrochloride (amidol) is not satis- factory for use under the conditions generally used for oxidative hair dyeins. The results for o-aminophenol and its derivatives are given in Table IV, and those for the diphenylamine derivatives are shown in Table V. Dyeing with Color Modifiers The color modifiers were dyed alone on natural white hair from 0.025 M solutions and from equimolar (0.131 M each) mixed with solutions