Note: Descriptions are shown in the official language in which they were submitted.
WO 93/21898 s~ PCI/US93/03630
HAIR DYEING COMPOSITIONS COMPRISED OF 5,6-DIHYDROXYINDOLE AND A
CHLORII'E OXIDANT AND MET~IODS C~F DYE,ING THEREWITH:
RELATED APPLICATION
This application is a continuation in part of commonly
owned and co-pending application Serial Number
07/875,874 filed April 4, 1992. ,
~,
FIELD OF THE INVENTION
.~.
This invention concerns methods and compositions for
dyeing human hair.
BACKGROUND OF THE INVENTION -;
`'".
Modern hair dyeing methodology has developed from` its
initiation in the 1950s to the point where today it is
the third largest product type in the hair care
category, following shampoos and conditioners.
~.,
One widely employed method for dyeing hair is based
upon the production of the natura} pigment me~lanin. The
exact structure of melanin it not known. It~is a
polymer produced from tyrosine by a series of metabolic
reactions the exact course of which remains to be
clarified. To take advantage of what has been ~`
elucidated with respe-t to the formation of melanin, it
.;
WO93/21898 PCT/US93/~3630
;~ 13 l ~Sl ~
has become the practice of the art to utilize 5,6-
dihydroxyindole (DHI) or 5,6-dihydroxyindole-2-
carboxylic (DHICA) as the dyeing agent. These compounds
have been clearly established as intermediates in the
pathway leading to the production of melanin.
There are a number of problems associated with the use
of DHI. It is difficult and expensive to synthesize and
is extremely unstable in air. It rapidly decamposes in
air to form other materials which are ineffective as
hair colorants.
. .
Diacetoxyindole (DAI) is used by the art in its
attempts to avoid these problems with DHI. The practice
has been to package DAI under mildly alkaline conditions
in packages designed to protect the ingredients from
air. Over the course of the time, between the initial
packaging and the final use, the DAI is hydrolyzed to ~
DHI. Since it is protected from air by the packaging, ;
the DHI remains stable until it is ready for use.
WO93/21898 ~ PCT~US93/03630
It is known that use of DHI alone requires a long
dyeout time. Therefore a variety of accelerators has
been emp~oyed to hasten the dye formation. Oxidants~
such as hydrogen peroxide, are the most widely employed
of the various accelerators which have been proposed.
The use of oxidants has not been particularly
successful with DHI, because oxidation takes place
before the DHI penetrates the hair. Ideally, the DHI
shou~d penetrate the hair before oxidation takes place
so that the pigment forms within the hair fiber. When
the colorant forms in this manner, the color does not
easily wash out. In contrast, if oxidation and melanin
formation take place in the solution there is little or
.
no dyeinq effect. If oxidation takes place on the
surface of the hair, the coloring is easily washed away
during shampooing.
..
In attempts to avoid these problems, the art has -
adoptedja two step process~ DHI is applied first and
allowed to penetrate into the hair. The oxidant is `
applied in a second step. This procedure is described,
for example, in US 2,934,396. Such procedures are `~
lengthy and inconvenient.
.
1.`
~. .`',
WOs3/21898 PCT/US93t03630
~t ~
It isi~ne object of this invention to provide a one-
step dyeing procedure, that is, a method, in which DHI ;
and oxidant are applied to the hair simultaneously.
Dyeing with DHI is very attractive to many consumers,
since its conversion to melanin is close to the natural `-
pigmentation process. However, there are disadvantages.
One such disadvantage is that, while natural hair color
comes in an inexhaustible variety of shades, many ;
oxidants which are used in combination with DHI dye the
hair only to a gray or black color with little or no ~
warmth. Extensive research efforts have been undertaken -
to find ways to modify the final color result after
dyeing with DHI.
One way to obtain a brown tonality is through use of
hydrogen peroxide. In this procedure, the hair is first -``
dyed black through formation of melanin and thcn `~;
partially bleached to brown through destruction of part
of the melanin. A clear disadvantage is the waste of ;~
DHI, which is supplied at the beginning. This is
important, because DHI is an expensive raw material, and
will control the price of the final product.
~ `:
W093/21898 ~ 3 i~ 1 PCT/US93/03630
.
A second disadvantage is the fact that uneven and
unpredictable results are often obtained due to the
heterogeneity of living hair and the difference in its
affinities for the dye, which vary from one person to
another.
A third disadvantage is the likelihood of oxidative
- damage to the keratin of the hair as a result of the use
of a product, containing peroxide - noticeable in a
coarse feel of the hair. Moreover, hydrogen peroxide is
normally used under alkaline conditions, with ammonia or
an amine as the alkaline reagent. These alkaline -
reagents impart strong~odors to the hair dyeing
compositions and are unacceptable to many users.
A fourth disadvantage is that peroxide attacks and
partly destroys the natural hair pigment. This weakens ~;
the hair and changes its feel and appearance~ -
: ~, , : ,,,
~ For these reasons, many efforts have been undertaken
' i'~
~ in--the~art to avoid the problems connected with the use
- of hydrogen peroYide. .
~' ~
.
~: . '
WO93/21898 PCT/VS93/03630
~ L
It is, therefore, another object of the invention to ;~
provide a method to dye hair to a dark brown shade
without using hydrogen peroxide.
Comparison with Prior art
. . ~
As described above, US 2,934,3g6 teaches that dyeing
with DHI requires two steps.
US 3,236,734 teaches dyeing with l-(alkylamino)-2,4-
dihydroxy benzene and an oxidant in one or two steps.
Chlorites, but not sodium chlorite specifically, are
mentioned among the oxidants said to be useful~, but
according to~the teaching of this patent, all oxidants
work equally well with the specified substrate, l-
(alkylamino)-2,4-dihydroxy benzene. ~his is clearly not i`~
~- the case, when DHI is used, as will be demonstrated
later in the examples (Example l). ;
Among the oxidants which are listed in US 3,236,734,
only chlorite and peroxide impart a deep color to the
hair ~DHI employed at equimolar concentration with the
substrates, which are taught in the patent).
WO93/21898 ,~ 6 ~ PCT~US93/03630
It should be understood, that under the heading
~peroxide~, there might also be compounds, which produce
peroxide after being dissolved in water; for exampl~,
perborate, percarbonate, urea peroxide and the like.
As will be shown in the examples, at a given
concentration of DHI and with equal dyeing time, sodium
chlorite gives the darkest coloration on hair, and -
provides the most economic use of the DHI.
,.j.
- US 3,194,734 teaches the use of a variety of oxidizing
agents with DHI or with l-,2- or 3- methyl substituted
DHI derivatives in alkaline media in a one- or two-step
process to color hair. Sodium chlorite is not mentioned -
in the patent. ~
: .
As will be seen in the examples (Example 3), among all
the oxidants, which are listed in the patent, only
peroxide gives useful results in a one-step dyeing
process with DHI. Moreover, in order to obtain dark
dyeings at a relatively low concentration of DHI, the
..
presence of a substantial amount of ammonia is required.
As stated above, this causes unacceptable odor problems.
W093/2~898
PCT/US93/03630
US 5,032,138 teaches dyeing with standard oxidation
dyes (primary intermediates and couplers) in combination
with chlorite. Melanin precursors are not included rn
the patent.
US 2,944,869 teaches dyeing of hair with o-diphenols
and an oxidant, selected from ammonium and alkali metal
iodates, periodates or persulfates. However, these
oxidants, when used in a one-step treatment with DHI,
give only weak colors on hair, since most of the DHI is
oxidized and polymerized in solution, before it can
penetrate the hair.
The art has long sought a suitable oxidizing agent
which ~can be employed without the problems discussed
above. More æpecifically, the art has sought dye
compositions which will produce melanin in hair and give
the hair a desirable color, with lasting wear qualities, ;
in shorter periods of time, while avoiding the use of
hydrogen peroxide and itæ resulting oxidative and
. . .
bIeaching damage to the hair.
,
~ ~ . :','
WO 93/21898 ~ 'L ~ ~ P(~/US93~03630
SUMMARY OF THE INVENTION
Oxidative hair dyeing compositions and methods for
their use have now been discovered which avoid many of
the problems of prior art compositions. These novel ;
compositions are characterized by the use of sodium
chlorite as the oxidi~ing agent. The use of sodium
chlorite, with 5,6-dihydroxyindoline, DHI or selected
analogs, homologs or derivatives thereof, or with these
compounds together with oxidizable primary intermediates ~`
and couplers, or together with DHICA or its lower alkyl ;~
esters, for example methyl to hexyl esters including ~-
straight chain and branched chain alkyl esters has not
been specifically taught or suggested by any of the
above citations nor, so far as the inventors are aware, -;
by any other prior art.
DHI and DHI derivatives, analogs and homologs which
may be employed in~the pract~ice of this invention ~;
include melanin forming compounds represented by the
formula: ;
o~Ln,
I :~
`,'~
` .:
.
WO93/21898 , G~j ~ PCT/US93/03630 ~-
wherein R represents hydrogen, alkyl, hydroxyalkyl,
aminoalkyl, an alkyl group containing up to eight carbon :
atoms; aryl or substituted aryl containing up to three
reaction inert substituents; Rl represents hyrogen or
alkyl containing up to six carbon atoms; and mixtures of
said compounds. The compound 5,6-dihydroxyindoline is
also useful in this invention because under the ~.
conditions employed, it is oxidized to dopaminochrome `~`
which rearranges to DHI. The DHI then converts to
melanin in accordance with the invention.
I '~'r'
''``,''.
The preferred N-substituted compounds of the present
invention are those of structure I where the N-
substituent, R, is hydrogen, alkyl, hydroxyalkyl,
aminoalkyl, containing l to about 8 carbon atoms in the ;~
moiety or a substituted or unsubstituted aryl wherein `~
aryl substituents are reaction inert substituents such
as OH, NH2, alkyl, alkoxyl, or NO2. The most preferred
compound is DHI.
`',`.
WO93/21898 ~ PCT/US93/03630
~.
// . .
For convenience, the invention will hereinafter be
described principally with reference to DHI, but it
should be remembered that the invention is applicable to .
all of the compounds within the scope of the above
generic formula and their equivalents. The various ;
compounds may be used alone or in numerous mixtures,
including mixtures with other oxidative dyes or with '~ f
DHICA or its lower alkyl esters, to achieve ~ variety of
shades and tonal qualities with hair fibers. -
`:j
It is most unexpected to find that this specific ~
oxidizing agent will accelerate the formation of -
melanin, but not to such an extent that DHI is oxidized ~.
appreciably before it is distributed in the hair fiber.
It is equally surprising and unexpected to find that
15 sodium chlorite imparts a dark brown color of natural .`
- appearance to the hair at relatively low concentrations -~
~ of DHI and without the use of ammonia or other amines. .`
.
A further surprising aspect of the invention is the
f inding that DHICA and its lower alkyl esters or
20 oxidizable primary intermediates and:couplers can be
W093/2]898 PCT/US93/03630
.. ! t` t .
~ '
employed in association with sodium chlorite and DHI to i
achieve a wider variety of tonalities in the treated i
hair. ~ ~;
There are many advantages to the compositions and ;~
methods of the invention. These include: ~
l. Nelanin is formed in the hair, imparting a brown -
color of natural appearance with relatively low `
concentrations of DHI. These low concentrations are
possible, because none of the melanin, which was already
;0 present in the fiber, or is formed during dyeing, is
destroyed. This results is cost savings for the ~
manufacturer as well as for the consumer. -
. . .
2. Melanin is deposited in a predictable and
reproducible way. Dyeing results are even and
appealing.
3. The dyeing procedure is simple (one-step) and
fast.
4. Sodium chlorite does not cause oxidative damage
to human hair or to the natural hair pigment, as does ~-~
hydrogen peroxide.
W093/2]898 PCT/US93/~3630
1 3 1 '
5. The wear quality of the colors produced in the ,
dyed hair is appreciably enhanced i.e. the original dyed
color is retained for a longer period of time.
, ~,,
6. The actual coloring of the hair can be performed
at a pH which is at, or close to, neutrality. -
7. The odor may be markedly reduced because ammonia
or amines are omitted from the compositions.
DETAILED DESCRIPTION OF THE INVENTION ;~
The compositions of -his invention as applied to human
hair, either living or in a wig or other artificial
device with implanted human hair, comprise an aqueous ^
vehicle which may contain a water miscible solvent, such ~`
as a lower alkanol, typically ethanol or isopropanol to
aid solubility, together with DHI, or other compound(s)
of the class defined above. Other compositions of the
invention may contain DHI and/or a derivative, analog or
homolog together with DHICA or lower alkyl ester, or a
primary intermediate/coupler combination. Of course, if
such combination is employed, it may contain more than
one intermediate or coupler to achieve a variety of ~'
shades.
.~
WO93/21898 PCT/US93/03630 ~
3~ ~ `
/y ~,
A typical aqueous composition of the invention as
applied to the hair may contain from about 0.1% to 3~, i
preferably 0.3% to 1.5% DHI or DHI analog, homolog or
derivative, and from about O.1~ to 5%, preferably 0.5~
to 4~ of sodium chlorite. It is generally preferred to
employ lower concentrations of the oxidizing agent when -
the concentration of DHI utilized is at the low end of
the range. The pH is normally from about 7 to g, but
some variation is acceptable. -
All percent by weights defined in this disclosure and
claims are percents by weight based on the total weight
of the composition.
~.
As stated above, the concentration of the DNI in the
composition as applied to the hair is from about 0.1 to
2%. It was also noted above that DHI is rather unstable ~;
and subject to air oxidation. It is therefore normally
packaged for commercial use in the form of DAI in a
slightly alkaline solution, under conditions that `
substantially exclude air. On storage, under alkaline -
conditions, the DAI hydrolyzes to form DHI. The `
molecular weight of DHI is about 60% lower than the
molecular weight of DAI. Accordingly, the concentration ` i~
of DAI in the original package will be higher than the ~`;
. ~.
WO93/21898 .~ u ~J.~ S1 PCTtUS93/03630 ~i
. .. ~. .
....
/,S ~,
concentration of DHI in the package as ready for use. `~
Of course, it is possible, if sufficient precautions are
taken, to prepare an original package containing DHI~
''.
If, in accordance with a second embodiment of this
invention, the DHI and oxidant are utilized together
with oxidizable primary intermediates and couplers
(hereinafter sometimes called ~reactants~), the amounts
of reactants will be about the same as utilized in
conventional oxidant compositions. The amounts which ~`
will be tinctorially effective will vary with the
selected reactants, as is well known in the art. The
skilled artisan will have no difficulty in selecting the -
reactants and the amounts to be employed. Generally
each reactant will be present in an amount of from about
O.Ol to 2%, preferably O.Ol to 0.5%. .
If DHICA or a lower alkyl ester of DHICA is employed
in a formulation of the invention, the amount employed
will typically be from about O.l to 1%. ~;
. .
The oxidant will be separately formulated to mix with :`
the other components just prior to use, as illustrated
in the examples. Thus, a product of the invention may ~
comprise a package containing two separate units of .
W0~3/21898 PCT/US93/03630 !p~'
`~, t~ 3 :
/G ~
aqueous compositions, one containing the oxidant, the
other containing DHI and, if employed, a primary
intermediate and a coupler.
~.
The term rrpackage" is used in the widest possible
sense. It includes retail packages such as might be `
sold to an individual consumer with both compositions in
the same box or other container. It includes also
separate compositions in large amounts, such as might be
sold to a beauty salon, whether or not the separate
compositions are sold in the same container and are
intended to be used together.
, .
The compositions of this invention are particularly
adapted for co-dispensing from a compartmentalized ?,
packsge,~ such as the containers described in U.S. Pat.
Nos. 3,241,722 and 4,103,772, the disclosures~of which l~
-are incorpor~ated herein by reference- In such co- 'r,
dispensing packages, which have been employed previously
with hydrogen peroxide dye systems, the reactants are
normally sealed in one compartment of the container and
the hydrogen peroxide in another, and the container is
constructed with means for mixing the separate ;
ingredients in the container so that the resulting ~ i~
~ - t . ~
composition exits the container after such mixing. ~
W O 93/21898 PC~r/US93tO3630 `
`/~ '~"
There are two procedures for mixing which are normally ;
employed. One utilizes an aerosol package and valve
adapted so that the compositions in the compartments~mix ~,
as they pas~ through the valve. In the other, the
partition between the compartments is frangible and the ~-',
container is formed with a mechanism which permits the
partition to be pierced, or otherw_se broken, 80 that
the compositions mix prior to dispensing. Depending
upon the design of the container, the resulting mixed -",
composition can be dispensed under aerosol pressure, by
simple pouring or by any other convenient method. `
, ~.
When such co-dispensing containers are emplo,yed with '`,
hydrogen peroxide systems, there is always danger of
1~
premature mixing because of accidental leakage through ¦,
: -,
the partition. As a result the dye forming ~eaction,
which is intended to take place in the open air takes l'~
place in a closed container thereby generating volumes !~
of oxygen which may result in explosive pressure. There
is no such danger when the oxidative salts of this
20 ~ invention are emp}oyed since the dye forming reaction
does not gener ~e oxygen.
,. ..
!`~
, .
.`
,
.
''-,
WO93/21898 ~ PCT/~S~3/03630
'/~
Any of the conventional oxidizable primary ~
intermediates and coupling agents used with ordinary - ~::
oxidant compositions for hair coloring can be employed
in the compositions of this invention to achieve, ~ .
together with the DHI, a wide variety of tints and hues.
Table l below lists some of the preferred primary .
intermediates and couplers for use in this invention.
TABLE l
Primary p-phenylenediamine
Intermediates: p-aminophenol .
o-aminophenol
N,N-bis(2-hydroxyethyl)p-phenylenediamine -
2,5-diaminopyridine
p-toluenediamine
Couplers: resorcinol
m-aminophenol -:
l-naphthol
5-amino-o-cresol
2-methylresorcinol
4,6-di(hydroxyethoxy)-meta-phenylenediamine
meta-phenylenediamine
''
W093/21898 PCT/US93tO3630 .
21 ~ 1 L~
' /~i; ~'
Well known conventional additives usually employed in
oxidative hair coloring compositions such as thickeners,
surface active agents, antioxidants and fragrances m~y
be included in the compositions of the invention. Such ...
compositions are preferably li~uid solutions, but they
may be in the form of emulsions, suspensions, lotions,
or gels. -i
~,
Surface active agents employed in the dyeing
compositions of this invention can be amphoteric,
anionic, nonionic or cationic. By way of examples of
the various types of surface active agents, there can be ~.
mentioned: higher alkylbenzene sulfonates:
alkylnaphthalen-sulfonates: sulfonated esters of
alcohols and polybasic acids; taurates; fatty alcohol -
sulfates; sulfates of branched chain or secondary !'
: '
alcohols; alkyldimethyl-benzylammonium chlorides, salts
of fatty acids or fatty acid mixtures; N-oxyalkylated .
fatty acid aIkanolamides, and the like. Illustrative of
specific surfactants there can be mentioned: sodium -
lauryl sulfate; polyoxyethylene lauryl ester; myristyl ~.
sulfate: glyceryl monostearate: triethanolamine oleate, ~`
sodium salt of palmitic methyl taurine; cetyl pyridinium !`
chloride; lauryl sulfonate: myristyl sulfonate; lauric
diethanolamide; polyoxyethylene stearate; ethoxylated
`:`
::
W093/21898 ~ ~j'}~ PCT/US93/03630
' ~0
oleoyl diethanolamide; polyethylene glycol amides of
hydrogenated tallow; stearyldimethyl benzyl ammonium
chloride; dodecylbenzene sodium sulfonate; 2-amino-25
methyl propanol; triethanolamine salt of p-
dodecylbenzene sulfonate; triethanolamine salt of p-
dodecylbenzene sulfonate; nonylnaphthalene sodium
sulfonate; dioctyl sodium sulfosuccinate; sodium N-
methyl-N-oleoyl taurate; oleic acid ester of sodium
isothionate; sodium dodecyl sulfate and the sodium salt `
of 3-diethyl tridecanol-6-sulfate and the like. The
quantity of surface active agent can vary over a wide
range, such as from about 0.05% to 15% and preferably
from about O.lO to 5% by weight of the composition.
-~ A thickening agent may also be incorporated in the `
dyeing composition of this invention which may be one or ~
several of those commonly used in hair dyeing. These `
are exemplified by such products as sodium alginate or
.
- gum arabic, or cellulose derivatives, such as
methylcellulose e.g.... Methocel 60 HG, or the sodium "
salt of carboxymethylcellulose, or
~.
hydroxyethylcellulose, e.g., Cellosize QP-40 or acrylic
polymers, such as polyacrylic acid sodium salt, or
inorganic thickeners, such as bentonite. The quantity
of this thickening agent can also vary over a wide
'
WOg3/21898 PCT/US93/03630
range, even as high as 20%. Ordinarily it will range
from about 0.5 to 5% by weight of the composition. The ~
viscosity of the composition may vary from about l cps ;
to about l00,000 cps. For a typical lotion formulation, '`x
composition viscosity is from about lOO cps to about
10, 000 cps.
It may also be useful to incorporate an antioxidant in ~
the present dye compositions. A variety of antioxidants ~;
- are known in the prior art which would be useful for ~`
this purpose. Among these mention may be made of the ;"?'
inorganic sulfites, e.g., sodium sulfite, thioglycollic
acid and other mercaptans, butylated hydroxytoluene,
sodium dithionite, various forms of ascorbic acid and ;~`
their derivatives, e.g., sodium aæcorbate, erythorbic
acid, ascorbyl palmitate, ascorbyl laurate, etc. The
guantity of antioxidant used can vary appreciably.
However, the concentration will, in general, be Up to
about 1%, typically O.OOl to 1%~ by weight. 1`~
. .
The dyeing compositions of this invention are
preferably aqueous compositions. The term aqueous
composition is used herein in its usual generic sense as
embracing any water-containing composition useful for
the present purposes. This includes true solutions of
. `~ .
W093/21898 ~3 ,~ PCT/US93/03630
the dye components aqueous medium, either alone or in
conjunction with other materials, which are also
dissolved or dispersed in the aqueous medium. The term
aqueous composition also encompasses any mixture of the
chlorite and the dye forming reactants with the aqueous
medium either alone or together with other ingredients.
The various components may be colloidally dispersed in
the medium or may merely be intimately mixed therein.
Moreover, the aqueous medium may comprise water or water
and an additonal or auxiliary solvent. Typical
auxiliary solvents which may be used to enhance the
solubility of the components include ethanol, carbitol,
isopropanol, propylene glycol, ethylene glycol,
diethylene glycol, diethylene glycol monoethyl ether, ~`
glycerine, etc.
The aqueous dyeing compositions of this invention can `
be prepared by conventional methods used in the hair
dyeing art. Thus, they can be preparod by dissolving or
suspending the components in the selected media with
adequate mixing.` Preparation may take place at ambient
temperatures, i.e., 20 to 35C., but solubility and
rate of preparation can be enhanced utilizing elevated
temperatures, for example 40 to 100C.
~ ' ~
`
W O 93/21898 ~ 1 3 `~; X ~ PC~r/US93/03630
~3
The compounds employed in this invention are all known
or can be prepared by known procedures.
By way of specific example but without limitation,
there follows a description of various known routes for ~
the preparation of derivatives of N-substituted-5,6- `
dihydroxyindoles which are useful in the present
invention.
(1) Synthesis by cyclization of a dopamine derivative:
, ....
A suitable 3,4-dihydroxy-N-substituted phenethylamine
material is converted by oxidative cyclization followed
by chemical reduction to the N-substituted-
dihydroxyindole as per the method for preparation of N-
methyl-5,6-dihydroxyindoles from epinephrine described
by G.L. Mattok-and R.A. Heacock in the Canadian Journal
of Chemistry, Volume 42, p.284 (1964t.
WO93~21898 PCTtUS93/03630
~ r.
For example, N-isopropyl-3,4-dihydroxyphenethylamine
(II~ can be oxidized by an alkaline ferricyanide
solution folllowed by reduction with ascorbic acid to ~ .
give N-isopropyl-5,6-dihydroxyindole (III):
.,
~or~ ~ o T~3
~0~ ''~ ~~ ~ ~`
~ ~`.
11 1~ ~
Similarly N-(4-aminobutyl)-5-6-dihydroxyindole (V) can
be obtained from 3,4-dihydroxy-N-(4-nitrobutyl)-
phenethylamine (IV): .
~X~ ~ 1'~3
~0 H0
- ~L `.
~~ .
(b) Synthesis by condensation of a benzenoid compound
and a nitrogen containing compound.
''.
.
. .
,
WO93/21898 ,~1 3 ~ ~1 PCl/US93/03630
An alternative synthetic procedure is available by the
methods described by A. Reissert in Chemische Berichte, ~`
Volume 30, page lO~O ~1897) and C.D. Nenitzecu in
Bulletin of the Chemistr~ Society of Rumania, Volume 11,
~:i
page 37 (1929) where the indole is produced upon the
condensation of a benzenoid radical with an appropriate
N-containing material. For example, N-(2-
hydroxyethyl)5,6-dihydroxyindole (VI) can be obtained ~.
upon oxidative coupling of catechol (YII) with N-vinyl
ethanolamine (VIII) followed by reduction.
HO~ ~ 9
(c) Synthesis by addition of indole to an aryl
compound is by the direct addition of the indole to an
aryl or benzyl halide or azide to give the aryl or -`
arylalkyl N-substituted-5,6-dihydroxyindole.
Specifically, 5,6-diacetoxyindole (IX) is reacted with `
2,4-dinitro-fluorobenzene (X) to give, after hydrolysis
of the acetate radicals, N-(2,4-dinitropheny)-5,-6-
dihydroxyindole (XI): F
WOg3/21898 ~ ~ PCT/US93/03630
t,,, ,-
The following examples are illustrative of this
invention and their use. They illustrate the advantages
of the compositions of the invention. ~ ~
The tristimulus values in the examples are standard -
Hunter chromacity values obtained by procedures well
known to those skilled in the art. The values recorded
manifest the ability of the compositions of the `
invention to be usefully employed in hair coloring
processes.
In the Hunter Tristimulus System, L is a measure of
lightness and darkness that is, the depth of the color
of the hair tress. The lower the value of L the darker
the color.
- A decrease in the value of L indicates a darkening of
the hair tress. In the case of bleached and blended
gray hair, a lowering of the value of L shows deposition
of hair dye on the tress.
The a value is a measure of the greenness or redness
of the hair's color. As the a value increases, the hair
has a more prominent red tonality. A lowering in the a
1.'`'`,
.
''``''~
WO93t21898 PCT/US93/03630 i
~ ~ 3 1 L~
,:`.
value results in greener shades. The b value is a
measure of the yellow and blue color. Higher b values
indicate a more yellow hue in the hair.
. . .
Example 1 1~
DHI WITH VARIOUS OXIDI ZING `~ .
AGENTS
~`~
A DHI composition was prepared containing l.85 parts
by weight of DHI, 0.2 parts by weight thioglycolic acid
(TGA -an antioxidant) and 78 parts by weight of water
adjusted to pH 6 . 5 with hydrochloric acid. This ~i
solution was employed as a standard solution to !,'`
determine the efficacy of a number of oxidizing agents
including those reported in United States Patent ;;
- 3, 236, 734 . ~ j .
~15 ~For each test, approximately 16 ml of the DHI solution
was combined with 4 g of an aqueous solution of the `
oxidant under test in the solutions defined in Table 2.
- The solution was applied to swatches of gray hair from ;
the same sourcç and left for 20 minutes. The treated `
hair was then rinsed, shampooed and dried. The dyeing
conditions tconcentrations, dyeing time, pH etc.) are ;~
ï ~
~ '
; ' .'.
! `
WO93t21898 PCT/US93/03630
. ~ .
chosen such that the experimental conditions of US
3,236,734 are reproduced as closely as possible : The -~
concentration of DHI is equivalent, on a molar basis~to
the concentration of the hydrochloride of 2,4-dihydroxy
phenylamine (Example 19 of US 3,236,734) and the
concentration of the oxidants, sodium iodate, potassium
persulfate, sodium perborate, is as described in this
example. Sodium bromate and sodium chlorate (listed in
the patent without specification of conditions) were "`
used at equimolar concentration as sodium iodate.
Under these conditions, only sodium chlorite (Entry 9)
and perborate (Entry 3) dye the hair to colors judged to
be useful based on darkness and tonality. Perborate -~
affords peroxide in aqueous solution. It is equivalent
to aqueous peroxide itself - or to other peroxide i-
sources, such as percarbonate, urea peroxide et cetera.
,
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WO93/21898 ~ PCT/US93/03630
' .
` ' .:.
~ABLE 2 ~ ~
Dveinq of Gra~ Hair With Formula A (Hiqh DHI concentration) ~ ?
., .
Entrv Oxidant, Add~d to 16cc DHI Solution E~ . L a ~, -
Color
1 0.4g NalO3, 0.4g HOAc, 3.2g H2O 4.6 35.60.4 6.7 Gray ~.-
,, .
2 0 8g X2S2o8, O . 4g HOAC, 2. 8G ~2 2 . 434 . 2 0 . 8 7 . 2 Gray
3 0-3g NaB03, O4g Na2C03, 3.3g H2O 9.2 22.80.9 2.3 Dk. Gray
4 0.4g Na8ro3, 0.4g HOAc, 3.2g H2O 4.427.3 -0.2 4.4 Gray !:~
0 . 4g NaClO3, 0 . 4g HOAc,3 . 2g H2O 4 . 5 34 . 4 0 . 6 6 . 5 Gray
1 0 6 4g aq. NaOCl ( 4-6~ ) 5 . 730 . 7 0 . 2 4 . 8 Gray
7 4g 6~ H2PO2 6.0 27.90.5 4.4 Gray
8 4g 6% H2O2, 04g urea 6.0 27.00.5 4.2 Gray i
9 0.2g NaClO2, 0.4g HOAc, 3.4 gH2O 4.418.7 0.6 1.6 Dk. Gray/Blk
.
a Undyed hair: L 35.8 a 0.2, b 6.6
Similar results are obtained with N-methyl- and N-ethyl-
5,6,dihydroxyindole and with the corresponding 2-methyl- and 2- .`
! ' `
~ ethyl-compoundS. `i~`~
i `,
.,
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WO93/21898 PCT/US93/03630
EXAMPLE 2
COMPARISON OF SODIUM CHLORITE (ENTRY II)
WITH OTHER OXIDANTS ;
This example was conducted to show the unexpected
superiority of sodium chlorite as an oxidant compared
with hydrogen peroxide or other~sources of peroxide,
such as perborate.
Formulations were prepared, which contained DHI at a
lower concentration than in Example l (DHI concentration
~ 0.5% after mixing with oxidant). This would be a
preferred concentration for a commercial product, since `
DHI is an expensive raw material. The formulations X
contain different alkaline agents to adjust the pH to i
the desired value. This is summarized in Table 3. `-
.
Entries l - 5 demonstrate, that, in contrast to sodium
chlorite, peroxide, or its substantial equivalent
perborate are only efficient as oxidants at alkaline pH.
~!
Entries 8, 9 and l0 show, that the efficacy of peroxide `
is further increased, when ammonia is used as the
alkalizing agent. '`
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WO93/21898 ~ PCT/US93/03630 ~;
3/
Entry ll illustrates the use of sodium chlorite. ;
The data demonstrate, that with peroxide as oxidant, the ..
efficacy of sodium chlorite can be approached (but still ~,.
not matched) only at high pH and high ammonia .`
concentrations both of which are unacceptable because of
the strong odor of ammonia and the likelihood of hair
damag~ at the high pH. Only sodium chlorite imparts a
deep brown color at low pH, without ammonia, from !,'
solutions containing relatively low concentrations of -~
DHI. ;`
T~BLE 3 ;~
~ .~.
DYeinq of Gra~ H~ir With Low Concentration of DHI 0.5a
y Oxidant (~) Ba-e(~) pHHunter Trist. val. color ,~
L a b
1 2 2 ( ) MEA (1.8) 9.9 27.6 ) 0.2 2.9 dark
gray
H22 (0-5) MEA 8.032.7 0.2 6.2 gray
3 N22 (0-5) MæA 7.032.4 0.4 5.9 gray
4 NaBO3 (l.Sl MEA 9928.3 0.2 3.0 dark
; gray
NaB03 (1.5) NEA 8.032.8 0.4 6.1 gray
6 NaBO3 (1-5) Et2NH(1.6) 10.5 27.8 0.3 3.3 gray ~`
., :
W O 93/21898 PCT/US93/03630
! :
7 NaBO3 (3-0) Et2NH~1~6) 10.5 27.3 0.4 3.4 gray
8 NaBO3 ~l.S) NH3 (O.S) 9.8 25.4 0.6 2.8 .dark
...
~ . gray
g NaBO3 (3.0) NH3 (0.5) 9.8 25.0 0.5 3.0 dark ~ .
NaBO3 (1.5) NH3 (1-3) 10.8 21.7 0.8 2.0 dark
~ gray .~
11 NaClO2 (3.6) 7.0 21.9 1.5 3.9 dark .:~.
brown .::.
, .
Similar results are obtained with~N-isopropyl-5,6-dihydroxyindole
and with N-(2,4-dinitrophenyl)-5,6-dihydroxyindole. ~.
, - .
:
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WO 93/21898 ~ ~ 3 ~ PCr/US93/03630
'~
~ ''~"~.
EXAMPLE 3
ADDITIONAL COMPARI SONS OF ~ `~
SODIUM CH~RITE , ,~`.-``.
......
This example was conducted to compare the efficacy of
S sodium chlorite with oxidizing agents specifically -
mentioned in United ~ ~.
States Patent 3,194,734.
The following compositions were prepared: (as described
in US 3,194,734)
~. .
,:
:, : : ,~
'~
WO93/21898 PCT/US93/~3630 ~
~x ~3 ~
FORMULA B FORMnLA C FORMULA D
~ ..
DAI 1 DAI 1 DAI 1 -
~onyl-Nonoxynol-49 9 Nonyl-Nonoxynol-49 9 Nony}-Nonoxynol-49 9
~ MEA 2 Ammonia (20~) 3 Ur~a 7.5
TGA (50~) 0.1 TGA (50%) 0.1 Diethylamine 2
Water 87.9 Water 86.9 TGA (50~) 0.1 .
Water 80.4
All components were dissolved in water with heating to about
50-60C, until complete dissolution of`the various ingredients. This !~
.
1~0 ;~ ~temperature increase brings about the deacetylation of DAI and
therefore the formation of 5,6-dihydroxyindole (DHI). 1 g DAI
results in approximately 0.64 g DHI.
-~ The ingredients and methods of preparation of the formulations
;~ ~ are identica1 to what has been~described in US 3,194,734 (examples
1,2 and 3) with one~exception: Nonyl-Nonoxynol 49 was used instead
~ of ~Cemulsol 132~, due to the unavailability of this component.
,
;Cemulsol 132 is~a non-ionogen condensation produet of ethylene oxide
and a naphthol compound. Nonyl-Nonoxynol 49 is a non-ionogen
condensation product of ethylene oxide and;a benzene compound. This
substitution has no effect on the described dyeing results.
~ ' '
W093/2~898 ~w ~ PCT/US93/03630
~ .
~5 ~ .
In each entry the oxidant was added immediately before use to :`
the formulation (ambient temperature), applied to hair and left.for .
20 minutes. The hair was rinsed with water, shampooed and dried.
Hunter Tristimulus values were measured.
,j.
The results are shown in Table 4. ,~
.~
~"
TABLE 4
DYein~ of GraY Hair with Formula~ B, C and D (Low DHI concentration)
q;
~ ;Dve SolutLon ~ L a b color ~r~
~.
1 lOce formula C, lce 6~ H2O2 10.0 22.5 1.2 1.0 Dk. Gray !:'
0 ~ 2 lOec formula D, 0.2g(NH4)2S2O8 9.2 31.9 0.6 4.7 Gray .;~
3 lOec formula C, 0.02g~CoCl2 9.9 27.6 0.0 2.7 Gray
4 lOce formula C, 0.02g Mn-lact. 9.2 29.4 -0.3 3.4 Blui~h Gray :`
~~^ formula ~, leC 6~ H202 9-9 26.8 0.2 2.8 Gray
`. formul~ _, 0.4g NaC1021n lg H20 7.0 21.C 1.5 3.9 Brown
.
: ~
WO93t21898 PCT/US93/03630
~G
a After addition of oxidant.
With H2O2 (Table 4, Entry 1), the darkness of t~e h~ir is
comparable to sodium chlorite (Table 3, Entry 6). However, the
tonality is different.
: .
To obtain a dark dyeing as in Table 4, Entry 1 (with rel. low DHI
concentration and H2O2 as oxidant) the presence of a substantial
-~ ~ amount of ammonia is required. Without ammonia at equal DHI-
~- concentration,~ the dyeing is weaker (see Table~4, Entry 5).
TonalitY: An example of Hunter Tristimulus values of natural dark
10 ~ and~me~dium brown hair is the following:
- ~ L a b
dark brown 16.0 1.8 2.6
; med. brown 23.6 3.0 6.9
It;is apparent that at a darkness level of L at about 22, the b-
~: _
5~; value should~be more than twice the amount of the a-value. This is
achieved with hair dyed with DHI/sodium chlorite (Table 4, Entry 6),
but not with hair dyed with DHI/H2O2 at the conditions of Entry 1,
- Table 4. Only the DHI/sodium chlorite dyed hair appears natural
brown.
:~
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WO93/21898 PCTtUS93/03630
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EXAMPLE 4
COMPOSITIONS CONTAINING PRIMARY INTERMEDIATE AND COUPLER
An aqueous solution, containing 0.3% DHI, 0.4% p-aminophenol, 0.4%
¦ 5-amino-o-cresol in a pH 7 phosphate buffer was prepared (solution
1). 3 ml of an aqueous solution of sodium chlorite (4 %) was added
to 5 ml of solution 1; the mixture was applied to (gray) hair and
left for 15 minutes. The hair was rinsed with water, shampooed and
dried. The hair had a medium brown color with Hunter Tristimulus
values L 21.8 a 1.9 b 5.1. If sodium chlorite was omitted in an
~ ~ otherwise identical dyeing solution, the hair was dyed to a light
¦ brown color having the Hunter Tristimulus values L 28.5 a 1.3 b 6.9.
; If DHI was omitted in an otherwise identical dyeing solution (with
j sodium chlorite), the hair wa~ dyed to a light brown color with
Hunter Tristimulus values L 27.9 a 2.l b 7.4.
' ~
~15 Similar results are obtained with N-methyl- and N-ethyl-
~ 5,6,dihydroxyindole and with the correspondlng 2-methyl- and 2-
j ethyl- compounds.
.
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