CA1338378C - Process for preparing dye composition containing 5,6- dihydroxyindoles and products - Google Patents

Abstract

A process for preparing dye compositions which comprises hydrolyzing a 5,6-diacyloxyindole with an alkaline hydrolyzing agent under substantially anaerobic condition and the products made by such process.

Description

-This invention relates to a process for preparing 5,6-dihydroxyindole dye compositions and to the products made by this process. More particularly it concerns a process and products of the aforementioned type that are useful in dyeing human hair and skin.
The 5,6-dihydroxyindoles have been found to be very useful in dyeing hair, and particularly human hair on the head. However, because of their inherent instability they have presented problems in their practical application. These instability problems are attested to in U.K. patent 797,174 and U.S. patent 4,208,183 which are concerned with ways and means for preparing stable compositions containing these indole dyes.
U.K. patent 797,174 describes a process for preparing a dye composition containing 5,6-dihydroxyindoles and dyeing hair therewith. In accordance with this patent the 5,6-dihydroxyindoles are employed in the form of the 5,6-diacetoxyindole compounds because of the stability of the latter. The diacetoxy compound is then deacetylated in aqueous solution with an alkalizing agent like monoethanolamine immediately prior to use, and the composition so formed is applied to hair.
It is to be noted that this process is carried out in the presence of atmospheric oxygen.
Whereas 5,6-diacetoxyindole can be used as a stable precursor for 5,6-dihydroxyindole its use still presents difficulties. Since the 5,6-dihydroxyindole is sensitive to oxidation by atmospheric oxygen, this can lead to high loss of this material due to its auto-oxidation outside the hair.
It has now been found that the above-mentioned difficulties can be avoided and stable compositions may be obtained if the alkaline hydrolysis of the 5,6-diacyloxyindole is carried out under anaerobic condition.
In the practice of this invention the 5,6-diacyloxyin-dole will preferably be mixed with the alkaline hydrolyzing agent in a container which is substantially sealed to the atmosphere and the hydrolysis to the 5,6-diacyloxyindole is permitted to take place slowly in this container.
In accordance with an embodiment of the invention, a process is provided for preparing a dye composition containing a 5,6-dihydroxyindole of formula H0 ~ I ~ Rl (I) H0 ~ I R2 which comprises mixing in the presence of water a 5,6-diacyloxyindole of formula R-C
11`~ / Rl 0 1 1 (II) C'0 ~ N~-~` R2 R~ o with an alkaline hydrolyzing agent in a container, rapidly sealing said container and permitting said 5,6-diacyloxyindole of formula II above to be slowly hydrolyzed to said 5,6-dihydroxyindole of formula I under anaerobic conditions, wherein:
(a) R in each case is the same or different and is an alkyl or aryl radical; and (b) R1 and R2 are the same or different and selected from the group consisting of hydrogen, alkyl and aryl.
According to another aspect of the invention, products are provided as made in accordance with above process.

~ 338378 _ 2a In accordance with another embodiment of the invention, an article of manufacture is provided in the form of a kit comprising an outer container having enclosed therein in a first inner sealed container comprising products made by the above process and a second inner closed container containing a composition comprising a metal salt solution capable of promoting the dyeing of hair with and which accelerates the development of color from, the 5,6-dihydroxyindole when the contents of the first and second inner sealed containers are applied to hair.
The acyloxyindoles that may be employed in the practice of the present invention correspond generally to the formula:

Il ~\ . / Rl C~O ~ N ~ R2 (II) R ~ ~

wherein R in each instance may be the same or different organic radical and particularly alkyl or aryl radicals.
When R is an alkyl radical it was to be any of a variety of such groups. This includes such groups as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, t-butyl, n-pentyl, n-hexyl etc. Similarly when R is aryl it may likewise be any of a variety of aryl radical. By way of example, mention may be made of such aryl radicals as tosyl, benzoyl, p-nitrobenzoyl, p-methoxybenzoyl etc. In the preferred forms of this invention R is a lower alkyl radical having from 1 to 4 carbon atoms and especially methyl.
R1 and R2 in formula II above may likewise be the same or different and may be hydrogen or an organic radical 1 338~-~8 2 b such as alkyl or aryl. When R1 or R2 is alkyl it may be such groups as, methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, t-butyl, n-pentyl, n-hexyl, etc. The preferred alkyl groups are those that contain l - 4 carbon atoms.
Wherein R1 and R2 is aryl it will-usually be phenyl or substituted phenyl radicals. In the preferred practice of this invention, however R1 and R2 will be hydrogen.
Most usually the indole employed will be 5,6-diacetoxyindole.
The quantity of 5,6-diacyloxyindole or 5,6-diacetoxyindole that will be employed in practising the present invention may vary somewhat. Generally this will account for from about 0.25% to about 2% by weight based on the total weight of the composition with the preferred concentration being from about 1% to about 2%
on the same weight basis.

The alkaline hydrolyzing agent that may be employed in carrying out the process of this invention may be any of a number of alkaline materials that is compatible with human use. These are exemplified by such compounds as monoethanolamine, sodium hydroxide, KOH, diethanolamine, NH40H, triethanolamine, morpholine. Very good results have been obtained with monoethanolamine which is the ~aterial of choice.

The quantity of alkaline hydrolyzing agent utilized in carrying out this invention may also vary and will be dependent on the quantity of diacyloxyindole that is employed. Usually at least the theoretical quantity of alkaline agent is used which will completely hydrolyze off the acyl groups from the diacyloxyindole compound i.e., at least 2 equivalents of alkaline agent. In the preferred practice from about 0.5~ to about 10% by weight of alkaline agent is incor-porated in a sealed container in accordance with the present inven- _ tion.

In adding the alkaline agent to the composition of this invention the effort is made to add sufficient so that the pH of the composi-tion is on the alkaline side and in the range from about pH 7 to about pH 11. The preferred pH will be about pH 9 to about pH 9.5.

Other ingredients may also be included in the compositions of this invention. Thus an aqueous or dilute aqueous alcoholic vehicle containing up to 30% by weight of alcohol may be utilized as the medium in which the hydrolysis of the 5,6-diacyloxyindole takes place. Still other ingredients may also be employed which will be determined mainly by the form that the product will take. The aqueous or aqueous alcoholic vehicle when employed will comprise from about 0% to about 95% by weight based on the total weight of the composition.

In the practice of the present invention a variety of sealed containers may be utilized to provide the anaerobic conditions under which the 5,6-diacyloxyindole is hydrolyzed. Thus, for example, the components may be sealed in an aerosol can or included in a dispenser tube. In preparing the product in an aerosol can the 5,6-diacyloxy-indole is dispersed or dissolved in an aqueous or aqueous-alcoholic vehicle. To this is added enough alkalizing agent so that the final pH is about 9-9.5 which will be in excess of about 2 equivalents. This mixture is then rapidly sealed in an aerosol can with a propellant (e.g.
hydrocarbon repellant) The hydrolysis of the 5,6-diacyloxyindole is then allowed to take place slowly in the aerosol can which would be under anaerobic conditions. This product then can be dispensed from the aerosol can when it is desired for use. This product has been tested for stability at 50 for 3 months and has been found to be satisfactory.

In addition to the ingredients mentioned above the aerosol products may also include other ingredients designed to improved the organoleptic qualities or facilitate the application of the product. Thus it may include detergents, foam stabilizers, foaming agents, cationic polymers to diminish skin staining, etc. When the aerosol products of this invention are dispensed from the aerosol can they come out as rich foams that generally range in color from light yellow or tan to off-white or white. As is generally understood by those skilled in the art, rich foams such as those produced by the product of Example 1 have a density in the range of 0.4 g/cm3 or less.

In an alternative method for preparing the products of this invention the ingredients are packaged in a dispenser tube. The conditions within the tube are anaerobic in character and, as in the case with the aerosol products, the 5,6-diacyloxyindole is permitted to slowly react with the alkaline agent to deacylate the diacyloxyindole compound to produce the 5,6-dihydroxyindole.
The products made up in the dispenser tubes may take the form of a gel or a shampoo. In preparing the product F

as a gel, the 5,6-diacyloxyindole is dissolved in an aqueous vehicle (usually 95% ethanol). This is dissolved in a thickened aqueous solution (generally 3-6% Carbomer 940, at pH 9.5). As hydrolysis proceeds, the pH will drop. This is compensated for by adding additional alkalizing agent (e.g. ca. 2 equivalents). The thickened solution is sealed in a tube, and hydrolysis is allowed to proceed slowly. The product is dispensed from the tube as necessary, and then the tube is resealed. No loss in the capacity to dye hair of the material remaining in the tube has been observed.

4a ~-- 1 3383~
In addition to the ingredients mentioned above, the gel product may also include other ingredients to improve the organoleptic qual-ities or facilitate application of the product. Thus, it can include detergents, cationic polymers to diminish skin staining, etc.

In preparing a product as a shampoo formulation, the 5,6-diacyloxyindole is dispensed in a shampoo base (e.g. Clairol Blue Shampoo), and alkalyzing agent sufficient to hydrolyze the acyloxy groups and adjust the pH to 9.5 (e.g. greater than 2 equivalents). The mixture is sealed in a suitable container and the 5,6-diacyloxyindole is allowed to hydrolyze slowly.

In addition to the ingredients mentioned above, the shampoo formulation can also include other ingredients to improve the organoleptic qualities or facilitate application of the product.
Thus, it can include, for example, cationic poly~ers to diminish skin staining, etc.

The hydrolysis of the 5,6-diacyloxyindole in accordance with this invention is not instantaneous but proceeds over time. For optimum results, sufficient time should be allowed for complete conversion of the 5,6-diacyloxyindole to the 5,6-dihydroxyindole as its mono or dianions. This will usually be about 18 hours at pH of about 9.5.

The package products of this invention and particularly the gel and shampoo packages containing the 5,6-diacyloxyindole do not have to be made under anaerobic conditions. All that is necessary is that they be stored closed to prevent further diffusion of oxygen into the container.

In applying the products of this invention to the dyeing of hair it is often advantageous to employ them in conjunction with a promoter composition which accelerates the development of color from the 5,6-dihydroxyindole compound. Certain metal salt solutions, and especially solutions of CuS04 are particularly useful for this purpose. These solutions will generally be used at a cosmetically acceptable pH, the optimum being approximately pH 9.5. The concen-tration of the salts in this solution will generally be in the range of from about 0.25~ to about 5~ by weight based on the total weight ~ 1 338378 ... ..
of the ~olution with the preferred range being from about 1% to about 2~ on the same weight basis.

In addition to the metal salt, and particularly CuS04, additional aids may be incorporated in the promoter composition.
These may serve to facilitate the application of the promoter to the hair, to assist in the dyeing operation or to improve the elegance of the product or to improve the condition of the hair. Thus, for example, the distribution of the CuS04 in a liquid shampoo com-position provides an effective means for getting it into the hair.

The application of the promoter composition wi ~ ordinarily take place as a separate step from the application of the 5,6-dihydroxy-indole composition. The order in which these compositions are applied is not critical, that is to say that the promoter composi-tion may first be applied to the hair followed by the application of the 5,6-dihydroxyindole composition or vice versa.

A convenient form for marketing the products of the present invention are as kits in which the promoter composition and the hair dye composition i.e., the 5,6-dihydroxyindole composition are each disposed in its own inner container and that both of these are packaged together in an outer container. With this arrangement the product is ready for use in the total hair treating and coloring operation.

The following examples are given to further illustrate the present invention. It is understood, however, that the invention is not limited thereto.

Aerosol Product Gms. ~ by Wt.
~1)5,6-diacetoxyindole C.2 1.0 (2) Monoethanolamine0.1 0.5 (3) H20 17.7 88.5 *(4) Propellant 152A 1.6 8.0 (5) Cetyl alcohol 0.4 _ 2.

* 75% difluoromethane/25% isobutane.

Procedure:

H20 is added to solid 5,6-diacetoxyindole placed in an aerosol can. The cetyl alcohol and monoethanolamine then are added to the can which is rapidly capped and sealed. Air then is evacuated from the can through the aerosol valve and the propellant then is introduced into the can through the aerosol valve.

Gel Product Gms. % by Wt.

(1) 5,6-diacetoxyindole 0.2 1.0 (2) Monoethanolamine 0.1 .5 (3) ** Carbomer 940 (.5% solution in H20) 19.7 98.5 *~ CTFA nomenclature for cross-linked polymer of acrylic acid.

Procedure:

The Carbomer 940 solution is mixed with the 5,6-diacetoxyindole. The monoethanolamine is then added and the product is rapidly loaded into a dispenser tube and sealed.

An alternative, preferred procedure is to dis601ve the 5,6-diacetoxyindole (e.g. 1-5% by weight) in alcohol (e.g. 95%
ethanol), then to add this solution to the thickened, alkalized -Carbomer 940 solution under aerobic conditions. The product is then loaded into the dispenser tube and sealed.

. ~ , .. . .

Shampoo Gms~ by Wt.

(1) 5,6-diacetoxyindole 0.2 1.0 (2) Monoethanolamine0.1 .5 (3) Shampoo *~* 19.7 98.5 20.0 100 **~ Shampoo Formula Ingredient % by Wt.

Disodium monococamide MIPA-Sulfosoccinate 10.0000 Methylparaben .1000 D&C Violet #2 .0008 FD&C Blue ~1 .0009 Quaternium - 6 1.0000 Imidazolidinyl Urea .2000 Ethylenediamine Tetra Acetic Acid .0500 Citric Acid .2000 Sodium Chloride .6000 Amphoteric - 12 4.5000 Quaternium - 22 2.0000 Ammonium Lauryl Sulfate -40.0000 Hydrolyzed Animal Protein .4000 Laureth - 23 .0100 Fragrance .2000 Water QS 100.

.
Procedure:

The 5,6-diacetoxyindole is mixed with the shampoo. Th~
monoethanolamine is then added and the product is rapidly loaded into a dispenser tube and sealed.

.

t ~- 1 338378 Promoter Composition Gms.% by Wt.

CuSO4 5 2 2.0 2 Monoethanolamine 5.0 5 **** Conditioner Formula 93.0 93 *t** Conditioner Formula Ingredient ~ by Wt.

Hydroxylethyl Cellulose 2.09250 Sodium Hydroxide 0.01395 Amphoteric - 2 2.38080 Cocamidopropyl Betaine 1.86000 Phosphoric Acid .42780 Quaternium - 40 4.65000 Ethoxydiglycol (and) Glycol (75-25) 2.79000 Sorbic Acid 0.09300 Quaternium - 15 0.09300 Fragrance - 0.03720 Water QS 100 The conditioner 601ution composition is first formed by sequentially dissolving each of the ingredients in water (or, after addition of the first ingredlent, the aqueous solution formed by addition of the previous ingredient).

The CuSO4 is then dissolved in the conditioner solution and then the monoethanolamine is added. This has the form of a thin solution. This product is then poured into a bottle and the bottle i S 8 ealed.

1 3~8378 Kits may be prepared by packaging in the same outer package the aerosol, gel or shampoo products prepared by Examples 1, 2 or 3 above with the promoter product prepared in accordance with Example 4 above. In addition to the two products, if desired, there may also be included in the kit any auxiliary equipment or composition that would be useful in the application of the products to hair on the human head.
A feature of kits embodied in this invention may be the inclusion of a solution which may be used to modify or remove the color that may be generated on the head of a subject using the hair dye compositions contained in these kits. One such solution is a freshly prepared diluted aqueous alkaline hydrogen peroxide (H2O2) solution, which can affect these changes in a few minutes.
An illustrative, but not limiting example of hair dyed by the kits described in Examples 1,2 and 3 is the following. Hair is treated with an amount of promoter sufficient to wet the hair. This solution is left on the hair for ca. 5 minutes. The hair is rinsed thoroughly, and the dyeing solution (sufficient for coverage) is applied for 5 minutes. The hair is shampooed and dried, leaving a black color.
In a separate example, the order of application may be reversed.
In a further example, hair dyed by either of the previous methods can be treated with dilute (1-6%) aqueous H202, adjusted to pH 9.5, to remove or modify the color as desired.

n.
.~, 11 1 3383~8 As previously disclosed, 5,6-dihydroxyindoles are known hair dyeing compositions. As further exemplification in this regard, United States patent 3,194,734 to Seemuller describes a process for dyeing hair with methyl substituted dihydroxyindoles which provide lighter color dyeouts than are provided by dihydroxyindole itself. The patent further teaches that alkaline solutions suitable for hair dyeing can be prepared immediately prior to dyeing by operating in a nitrogen atmosphere or by adding antioxidants such as thioglycollate, sulfite or the like. Based on the teachings of the prior art such solutions are not believed to have storage stability. The examples of the patent clearly show that, in presence of antioxidants, only weak colors such as light ash blond, gray, and bluish-gray are obtained by use of 5,6 dihydroxyindole unless extremely high levels of dye are employed. With the process of the present invention dark black dyeouts are produced, even after prolonged storage using very low levels of dye.
U.S. 4,208,183 teaches the preparation of storage stable solutions of dihydroxyindoles in alcoholic solvents. Prolonged storage of dihydroxyindoles is possible by this method, but these alcohol solutions are not suitable for dyeing hair, which is a serious disadvantage. Therefore, these storage stable solutions of the dihydroxyindoles must be mixed with a suitable cosmetic vehicle immediately prior to dyeing. The preferred method disclosed involves a dual compartment aerosol package. The reference does not disclose employing or storing the dihydroxyindoles under anaerobic conditions.
The present invention allows for storage in an aqueous medium which is suitable for dyeing hair directly rather than requiring a complex change of solvent and delivery system.

~ 12 l 338378 While 5,6-dihydroxyindole can be used as stable precursor for 5,6-dihydroxyindole, its use still presents difficulties since the 5,6-dihydroxyindole in sensitive to oxidation by atmospheric oxygen. This can lead to high loss of the dihydroxyindole due to its auto-oxidation outside the hair.
As already explained in the principal disclosure, the above mentioned difficulties can be avoided and stable compositions may be obtained if the alkaline hydrolysis of the 5,6-dihydroxy protected compound of formula II is carried out under anaerobic conditions. To facilitate discussion of further aspects of this invention, the protected compounds shall be referred to as O-protected 5,6-dihydroxyindoles. By the term 0-protected, it is understood to refer to an acyloxy groupof formula II or a sulfur containing group (both of which are exemplified in the following formula III) where the protecting group is hydrolyzed to the free hydroxyl under alkaline conditions by use of a suitable alkaline hydrolyzing agent.
By the process of the present invention it is possible to produce storage stable, ready-to-use alkaline solutions of 5,6-dihydroxyindoles, which surprisingly do not form melanins until applied to the hair (or skin).
Thus, much lower dye concentrations are needed to obtain dark dyeout. In the practice of this invention compound formula (II) or (III) will preferably be mixed with the hydrolyzing agent in a container which is substantially sealed to the atmosphere and the hydrolysis of compound formula (II) or (III) is permitted to slowly take place in this container. The present invention allows for storage in an aqueous medium which is suitable for dyeing hair directly rather than requiring a complex change of solvent and delivery systems.
According to another aspect of the invention, a process for preparing a dye composition containing a 5,6-dihydroxyindole of formula:

H ~ R21 (I) which comprises mixing in the presence of water an O-protected 5,6-hydroxyindole of formula:

~ N1 ~ R12 (III) 4~11 H
()n at a level of from about 0.25~ to about 2~ by weight with an alkaline hydrolyzing agent in a container, rapidly sealing said container and permitting said compound of formula (III) above to be slowly hydrolyzed to said 5,6-hydroxyindole of formula (I) under anaerobic conditions, wherein (a) Rl and R2 vary independently and may be hydrogen, methyl or ethyl, and (b) when X=S, n=2, R3 and R4 vary independently and are Cl-C6 alkyl, substituted phenyl, and (c) when X=C, n=l, R3 and R4 vary independently and may be Cl-C6 alkyl, substituted phenyl and substituted benzyl.
According to another aspect of the invention, an article of manufacture is provided as a kit comprising a container having enclosed therein in a first sealed .~

container containing compositions prepared in accordance with the above process and a second sealed container containing a composition comprising a metal salt solution present in an amount sufficient to promote the dyeing of hair with and which accelerates the development of color from the 5,6-di-hydroxyindole when the contents of said first and second sealed containers are applied to hair.
The O-protected hydroxyindoles that may be employed in the practice of the present invention correspond generally to the formula:

~ ~ Rl (III) /lXI
R4 ~0)n wherein R1 and R2 vary independently and may be hydrogen, methyl or ethyl. When X=S, n=2, R3 and R4 vary independently and maybe C1-C6 alkyl and substituted phenyl. When X=C, n=l, R1 and R4 vary independently and maybe C1-C6 alkyl, substituted phenyl and substituted benzyl. Typical of the alkyl groups which may be employed are methyl, ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, t-butyl, n-pentyl, n-hexyl, etc. In the preferred forms of this invention lower alkyl radicals having from 1 to 4 carbon atoms and especially methyl are employed.
The O-protected 5,6-dihydroxyindole of formula III
can be formulated under anaerobic conditions in accordance with the methods defined in the principal disclosure to prepare the various compositions. The O-protected 5,6-dihydroxyindole is present in the composition in the amounts ranging from 0.25~ to about 2 by weight and preferably 1~ to about 2~ by weight. The alkaline hydrolyzing agents employed are preferably the same for effecting the hydrolyzation of the O-protected 5,6-dihydroxyindole. Usually at lest the theoretical quantity of alkaline agent is used which will completely hydrolyze off the protecting groups from the O-protected compound of formula III; that is at least 2 equivalents of alkaline agent preferably from about 0.5~ to about 10 by weight of alkaline agent is incorporated in a sealed container in accordance with this present invention. The O-protected 5,6-dihydroxyindoles are mixed into the composition in accordance with the procedures of this invention, such as in aqueous or dilute aqueous alcoholic vehicles. They may be incorporated in aerosol cans, dispenser tubes, shampoo bottles or the like. In this manner, the compounds of formula III are permitted to slowly react with the alkaline agent to deprotect the O-protected 5,6-dihydroxyindoles.
The process of this invention provides compositions by virtue of the anaerobic environment in which they are formulated to carry out the hydrolysis and provides a significant advance over the prior art approach of using reducing agents. It is believed that the reducing agents typically employed in prior art compositions adversely affect the dyeout, oxygen being a critical reactant in the formation of melanin from 5,6-dihydroxyindole and that the anhydrous organic solvents interfere with hair dyeing. The stabilized system of the present invention provides a dark black dyeout after storage. A series of comparisons using a Cu+2 pre-treatment cléarly demonstrate these differences and the need for anaerobic conditions.
These comparisons are set forth in Table I.

~?
, , ~ 16 l 3383~
TABLE I
Hunter tristimulus values*
L a b Untreated blended gray hair 32.24 -0.64 6.26 1% 5,6-diacetoxyindole 12.19 -0.4 -0.06 (anaerobic, pH 9) 1% 5,6-diacetoxyindole 27.63 -0.64 5.22 (aerobic, pH 9) 2% 5,6-diacetoxyindole 9.93 -0.09 0.12 (anaerobic, pH 9) 1% 5,6-diacetoxyindole 16.69 -0.45 0.75 (in 100% ethanol) Nice 'n Easy 122~ 9.52 0.23 0.53 Natural black * Hunter values are a measure of reflected light and describe the color along three axes:
L = 0 is black, L = 100 is white. The more positive "a"
is, the redder the color, the more negative "a" is, the greener the color. Yellowness increases with increasing "b" value. Blueness increased with decreasing "b" value.
Although preferred embodiments of the invention have been described herein in detail, it will be understood by those skilled in the art, that variations may be thereto without departing from the spirit of the invention or the scope of the appended claims.

Claims (32)

1. A process for preparing a dye composition containing a 5,6-dihydroxyindole of formula (I) which comprises mixing in the presence of water a 5,6-diacyloxyindole of formula (II) with an alkaline hydrolyzing agent in a container, rapidly sealing said container and permitting said 5,6-diacyloxyindole of formula II above to be slowly hydrolyzed to said 5,6-dihydroxyindole of formula I under anaerobic conditions, wherein (a) R in each case is the same or different and is an alkyl or aryl radical, and (b) R1 and R2 are the same or different and selected from the group consisting of hydrogen, alkyl and aryl.

2. A process according to Claim 1 wherein R is lower alkyl and R1 and R2 are lower alkyl or hydrogen.

3. A process according to Claim 2 wherein said alkaline hydrolyzing agent is monoethanolamine.

4. A process according to Claim 3 wherein R is methyl and R1 and R2 are hydrogen.

5. A process according to Claim 4 wherein the quantity of 5,6-diacetoxyindole employed is in the range of from about 1% to about 2% by weight based on the total weight of the composition prepared and said monoethanolamine is employed in the range of from about 0.5% to about 1% by weight also based on the total weight of the composition prepared.

6. A process according to Claim 1 in which said hydrolysis takes place in a sealed aerosol can.

7. A processing according to Claim 2 in which said hydrolysis takes place in a sealed aerosol can.

8. A process according to Claim 3 in which said hydrolysis takes place in a sealed aerosol can.

9. A process according to Claim 4 in which said hydrolysis takes place in a sealed aerosol can.

10. A process according to Claim 5 wherein said hydrolysis takes place in a sealed aerosol can.

11. A process according to Claim 1 in which said hydrolysis takes place in a sealed tube.

12. A process according to Claim 2 in which said hydrolysis takes place in a sealed tube.

13. A process according to Claim 3 in which said hydrolysis takes place in a sealed tube.

14. A process according to Claim 4 in which said hydrolysis takes place in a sealed tube.

15. A process according to Claim 5 wherein said hydrolysis takes place in a sealed tube.

16. The dye composition containing 5,6-dihydroxyindole made by the process of any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15.

17. As an article of manufacture a kit comprising an outer container having enclosed therein a first inner sealed container containing compositions prepared in accordance with the process of any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 and a second inner closed container containing a composition comprising a metal salt solution capable of promoting the dyeing of hair with and which accelerates the development of color from, the 5,6-dihydroxyindole when the contents of said first and second inner sealed containers are applied to hair.

18. As an article of manufacture a kit comprising an outer container having enclosed therein a first inner sealed aerosol containing compositions prepared in accordance with the process by any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 and a second inner closed container containing a solution containing CuSO4, said CuSO4 being present in an amount sufficient to promote the dyeing of hair with and which accelerates the development of color from the 5,6-dihydroxyindole when the contents of said first and second inner containers are applied to hair.

19. As an article of manufacture a kit comprising an outer container having enclosed therein a first inner sealed tube containing compositions prepared in accordance with the process of any one of claims 11, 12, 13, 14 or 15 and a second inner closed container containing a solution of CuSO4, said CuSO4 being present in an amount sufficient to promote the dyeing of hair with and which accelerates the development of color from, the 5,6-dihydroxyindole when the contents of said first and second containers are applied to hair.

20. As an article of manufacture a kit comprised of an outer container having enclosed therein a first inner sealed container containing compositions prepared in accordance with the process of any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15, a second inner closed container containing a composition comprised of metal salt solution capable of promoting the dyeing of hair with and which accelerates the development of color from, the 5,6-dihydroxyindole when the contents of said first and second inner containers are applied to hair and third inner closed container contains an aqueous hydrogen peroxide solution.

21. A process for preparing a dye composition containing a 5,6-dihydroxyindole of formula:

(I) which comprises mixing in the presence of water an O-protected 5,6-dihydroxyindole of formula:

(III) at a level of from about 0.25% to about 2% by weight with an alkaline hydrolyzing agent in a container, rapidly sealing said container and permitting said compound of formula III to be slowly hydrolyzed to said 5,6-dihydroxyindole of formula I under anaerobic conditions, wherein (a) R1 and R2 vary independently and may be hydrogen methyl or ethyl, and (b) when X=S, n=2, R3 and R4 vary independently and are C1-C6 alkyl, substituted phenyl, and (c) when X=C, n=1, R3 and R4 vary independently and may be C1-C6, alkyl, substituted phenyl and substituted benzyl.

22. A process according to Claim 21 wherein X is S and n is 2.

23. A process according to Claim 21 wherein X is C and n is 1.

24. A process according to Claim 22 wherein said alkaline hydrolyzing agent is monoethanolamine.

25. A process according to Claim 23, wherein said alkaline hydrolyzing agent is monoethanolamine.

26. A process according to Claim 24 or 25, wherein said monoethanolamine is employed in the range of from about 0.5% to about 1% by weight based on the total weight of the composition.

27. A process according to Claim 21 in which said hydrolysis takes place in a sealed aerosol can.

28. A process according to Claim 21 in which said hydrolysis takes place in a sealed tube.

29. As an article of manufacture a kit comprising a container having enclosed therein a first sealed container containing compositions prepared in accordance with the process of Claim 21 and a second sealed container containing a composition comprising a metal salt solution present in an amount sufficient to promote the dyeing of hair with and which accelerates the development of color from, the 5,6-dihydroxyindole when the contents of said first and second sealed containers are applied to hair.

30. A kit according to Claim 29 wherein said first sealed container is an aerosol can and said metal salt in said second sealed container is CuSO4, said CuSO4 being present in solution.

31. A kit according to Claim 29, wherein said first sealed container is a sealed tube and said metal salt in second sealed container is CuSO4, said CuSO4 being present in solution.

32. A kit according to Claim 29 having a third sealed container wherein said first sealed container contains 5,6-dihydroxyindole, said second sealed container contains a composition comprised of metal salt solution capable of promoting the dyeing of hair with, and which accelerates the development of color from, the 5,6-dihydroxyindole when the contents of said first and second containers are applied to hair, and said third sealed container contains an aqueous hydrogen peroxide solution.