392 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table X Phenylmnines Used for Coupling with the Para Cronpounds 14. Aniline 15. 0-Phenylenedia•nine 16. m-Phenylenedimnine 17. m-Toluylenediamine 18. 2,4-Dimninoanisol 19. Nitro-m-phenylenedimnine NH2 NH2 NHz 0CHa NHz NH•z NH2 NH• CH,• NH,• NH• N02 Ntt,2 NH2 Experimental Results Of the possible 95 indophenols or indamine dyes that can be prepared from the intermediates listed, 80 have been made and tested, including all possible 19 each from p-aminodimethylaniline, p-aminoacetanilide, and p-aminophenol. The results of the substantivity, light fastness, and ageing tests, and a description of the color produced on dyeing hair are summarized in the tables given in the supplements to this paper. A com- plete range of colors can be obtained with these dyes. Of the 80 dyes tested, 8 failed the substantivity test. Of the 72 remaining dyes, 42 failed the light fastness test, and 50 failed the ageing test. This is possible be- cause 32 dyes failed both the light fastness and ageing tests. Ten of the dyes passed all three of these tests and varied, in the shades produced on hair, from a yellow, to an orange, to a pink, and to several shades of brown. All of the blue or gray shades, in this series, failed to pass either the ageing or light fastness tests or both. The presumed structures of the dyes that passed these three tests are shown in Table XI. Dye number D-1 cannot be included in the above table and so its presumed structure is given separately.

COLORING WITH SEMIPERMANENT DYES Table XI Structure of Dyes that Passed the Three Tests 2 t 3 • 3 2 6 • 5 t 5 6 393 Dye 1' 1 2 3 5 6 A-11 A-13 B-11 B-12 B-13 C-9 C-12 C-13 C-14 --N(CHa)2 --N(CH,•)2 H --NCOCH• H --NCOCH:i H --NCOCHa --OH --OH --OH --OH --:NH . . . --NO s •NH OH --NO• •NH ... --NO s ::O ... --NO • -•NH --0 H --NO s •0 . . . --NH• •O ß ß ß --NO2 •NH --OH --NOs . . . --NOs ß . . ß . . --NO• ß . • ß . . --NO2 , . o rOH --OH --NH2 ß , . ß . ß --NHs ß ß o --NH• Dye D-1 (CH,,3s Although the proposed structures have been given in one form, it has been known, for many years, that the indophenols and indamines exist in two tautomeric forms in equilibrium as reported by Vittum and Brown (38). Certain of the indophenol type dyes behave as indicators, giving one color in alkaline solution and a different color in acid solu- tion. The 10 dyes listed above were tested by comparing solution colors at pH values of 4.0 and 11.0. With the exception of dye D-l, no signi- ficant differences in co]or of acid and basic solutions, of the same dye, were noted. However, the basic solution of D-1 was a very dark green-blue and the acid solution a dark bright wine-red, indicating that this dye is unsatisfactory for use in semipermanent colors. These 10 dyes may be recrystallized from isopropanol, but the yields were, in all cases, very poor. In fact, with some products the til- trate had to be concentrated before crystallization occurred. For this reason a series of 11 solvents, some of which had been reported in the literature as being suitable for indophenols and indamines, were tried on