4:12 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 3. Tertiary dyes of the benzene series (3), of the type R• NI-I (CH2)n N NI-I {CH2)n N NO2 R• NH• and NH• NO• 4. Quaternary dyes of the benzene series (4), of the type + NH (CI-I•)n N NO2 a.s.o. NH• As regards tertiary or quaternary dyes, especially of the anthraquinone series, a very large number have already been synthesized during the past fifteen years. Their use has been mainly conceived in terms of the dyeing of synthetic fibres and, less commonly, wool. Though the chemical composi- tion of wool is very close to that of hair, the problems involved in the dyeing of hair are very different from those met with in wool-dyeing. This fact is well known to all cosmetic chemists. It was therefore interesting to attempt to introduce into the field of cosmetic application, dyes of so rich a series as that of anthraquinone, and also to create new ones specially suited to hair. On the first count, the first attempt was made recently (4), and two dyes having the formulation + • NH---CH2--CI-I•--CH•N (CHa)a and q- • l• o NH½ have been proposed.

SYNTHESIS OF SOME NEW QUATERNARY DYES 413 With the help of these dyes, white hair is dyed red and blue respectively. In the present work (5), an attempt has been made to enrich and enlarge the field of application of anthraquinone dyes for cosmetic purposes by synthesizing and studying a few new dyes, corresponding to the three following series: (Series I) 0 OH A- (Series II) o ,, OH '• N--R• o (Series III) In the above, R• and R2 are lower alkyl residues which, in Series I and II, can also form part of a heterocyclic residue such as, for example, a morpholine or piperidine residue. In every case R3 is a lower alkyl residue A- is a halogen or methosulphate anion, and n is a whole number equal to 2 or 3. The following compounds may be mentioned specifically: Methyl[2-(fimethyl morpholinium) ethylamino-anthraquinone] sulphate, methyl[2-(fimethyl diethyl ammonium) ethylamino-anthraquinone] sulphate, methyl [2-(fitrimethyl ammonium) propylamino-anthraquinone] sulphate, methyl[1-hydroxy 4-(Froethyl piperidinium) propylamino-anthraquinone] sulphate,