US3118724A

US3118724A - Processes for reduction of organic substances with alkali-metal borohydrides in the presence of catalysts

Info

Publication number: US3118724A
Application number: US765737A
Authority: US
Inventors: Goerrig Dieter; Schubert Friedrich; Weise Eberhard; Soll Manfred; Lang Konrad
Original assignee: GOERRIG
Current assignee: GOERRIG
Priority date: 1957-10-11
Filing date: 1958-10-07
Publication date: 1964-01-21
Anticipated expiration: 1981-01-21

Description

as L'//0S se 3,118,724 PROCESSES FOR REDUCTION OF ORGANIC SUB- STANCES WITH ALKALI-METAL BOROHY- DRIDES IN THE PRESENCE OF CATALYSTS Dieter Goerrig, Lohmar, Siegkreis (Farbeuiabrikeu Bayer AG., Leverkusen-Bayerwerk), Leverkusen Bayerwerk, Eberhard Weise, Cologne-Mulheim, and Manfred S01] and Konrad Lang, Leverkusen, Germany; said Schubert, Weise, Soil, and Lang assignors to said Goerrig No Drawing. Filed Oct. 7, 1958, Ser. No. 765,737 Claims priority, application Germany Oct. 11, 1957 6 Claims. (Cl. 8-34) This invention relates to alkali-metal borohydrides and similar boron compounds as reducing agents.

It is known that alkali-metal borohydrides can be employed as reducing agents. However, this method has the disadvantage that in most of the technically valuable cases, reduction proceeds too slowly.

It has now been found that the rate of reduction with alkali-metal borohydrides and similar boron compounds can be increased by carrying out the process in the presence of the following catalysts, or of mixtures of these catalysts:

(a) Metal sols of those metals which possess a solution potential nobler than l.5 volts at a pH value 7.

(1:) Complex compounds from which the metal on which they are based can be separated in the presence of a reducing agent at a redox potential between and 1 .5 volts at a pH value between 8 and 15.

(0) Inorganic compounds which are components of an inorganic redox system the potential of which lies between 0 and l.5 volts at a pH value between 8 and l5.

(d) Organic compounds which are components of an organic redox system the potential of which lies between 0 and -l.5 volts at a pH value between 8 and i5, and where the reduction of this organic redox system involves hydrogenation, or where its oxidation involves dehydrogenation.

In addition, the rate of reduction is often favorably influenced by addition to the above catalysts or catalyst mixtures of compounds of tetra-valent sulfur, such as, e.g., sodium bisulfite or sodium sulfite, or compounds which can form the sulfite or bisulfite ion by the action of water, such as e.g. sulfur dioxide, the metabisulfites or the dithit nates and dithionites.

Examples of metal sols mentioned under (a) are metal sols of tin, arsenic, copper, molybdenum, nickel, cobalt, or platinum. The preparation of metal sols wherein the metal is present in the colloidal state may proceed according to known methods, e.g., by reduction of soluble metal compounds, but it has been shown that frequently, e.g., for copper, nickel or tin, the activity of such metal sols is superior when they are obtained by reduction of a soluble metal complex compound. It is advisable to add protective colloids, e.g., glue, to the metal sols, in order to attain greater stability of such sols.

It is not necessary that the metal sols employed according to the invention contain the metal in its pure form, but in a given case they may still contain impurities, such as, e.g., hydrides, oxides, or borides.

Examples of the metal complex compounds mentioned under (b) are the complex compounds of the metals copper, cobalt, nickel, antimony, molybdenum, tin, or chro- United States Patent 0 Friedrich Schubert,

mium, whereby the complex forming components may be, e.g., glycol, ethanolamine, ethylenediamine, p-diketones, a-hydroxycarboxylic acids, or similar compounds. Furthermore, e.g., ammonia, hydroxyl (OH-) ions, and halogen ions may also be employed for complex formation. As examples of such compounds, the following are listed:

Na [SnF Cr,(SO,) .xCH -C0(CH) C0-CH, wherein at is a whole number.

The preparation of these metal complex compounds may be carried out according to known methods, e.g., by reaction of a metal salt with the complex forming agent, e.g., ethylene diamine. For this purpose, it is in general useful to employ an excess of complex forming agents, so that the metal compound on which the complex is based is brought into solution.

Examples of the inorganic compounds mentioned under (c) are, e.g., the complex alkali-metal cyanides of bivalent nickel, cobalt, chromium, or manganese, or alkali stannite +OH-ions, or alkali stannate. For this purpose, it does not matter whether the compound employed according to the invention is added in its reduced form (cyanocobaltate (ll), for example) or in its oxidized form (cyanocobaltate (III), for example).

Examples of the organic compounds mentioned under (d) are the anthraquinones and their substitution products, such as, e.g., anthraquinone-Z-sulfonic acid, l-aminoanthraquinone-8-sulfonic acid, l-amino-4-bromo-anthraquinone-2-sulfonic acid, 4-amino-anthraquinone-6-sulfonic acid, N,N dihydro anthraquinone-azine-3,3'-disulfonic acid, naphthol, indigo-trisulfonic acid or di[anthraquinonyl-( l ]-amine.

In the case of the boron compounds employed according to the invention, use is made, e.g., of alkali-metal borohydrides or borazanes or their dehydrogenation products such as the borazenes or borazines or their derivatives substituted by organic residues, e.g., alkyl or alltoxy groups, or compounds of the formula:

Furthermore, mixtures of such boron compounds may also be employed.

Although the catalysts described in the invention already exhibit good activity when they are employed alone,

it is nevertheless frequently of advantage to use a mixture of these catalysts. By this method, he side reactions occurring in many cases can be still farther suppressed or altogether avoided.

Moreover, when use is made of the mixtures of catalysts, the activity of the catalyst mixtures is in many cases essentially higher than was to be expected by addition of their individual activities, so that there exists a synergistic effect.

In some cases, several of the described catalysts exhibit a particularly good activity for quite specific compounds which are to be reduced. This selectivity can in many cases be suspended or extended by combination with an- 3 other catalyst, whereby a good properties of the catalysts is obtained. For example, the salt of anthraquinone-Z-monosulfonic acid already acts at room temperature to accelerate strongly the rate of reduction of quite specific vat dyestuffs. On the other hand, the salt of l-aminc-4-bromo-anthraquinonc-2-sulfonic acid causes acceleration of the reduction rate only at relatively much higher temperatures. However, a combination of these two compounds causes a strong acceleration of the reduction rate for organic compounds already at room temperature, whereby selectivity can no longer be observed.

Furthermore, favorable results are attained, e.g., when use is made of the heavy metal sols' or heavy metal complex compounds mentioned under (a) and (b) in admixture with the catalysts mentioned under (d) which form components of definite organic redox systems. It is known that metal sols exhibit the property of ageing gradually at higher temperatures, so that after some time at higher temperatures the activity of these compounds relaxes somewhat. Now, the addition of the above mentioned other catalysts appreciably increases the resistanceto ageing of such metal catalysts, since at lower temperatures it is possible to work with thesame or improved activity of the catalysts.

The catalysts or catalyst mixtures may be employed in amounts of 1-20%, preferably of 5-l0%, referred to the employed boron compounds, particularly to alkali-metal borohydrides. In some cases, it may be desirable to use still different proportions. Preliminary experiments can readily establish which catalyst combination will prove the most favorable in any individual case. The employed catalyst combinations act with particular advantage when they are added to the dye baths during dyeing with vat dyestuffs with the aid of boron compounds as reducing agents. However, the catalyst combinations may combination of the desired of the activity of the catalyst, a 10 g. piece of cotton fabric pen ions and left there at 60 C. for 1 hour, whilst the pieces of fabric are turned in the suspensions from time to time. Thereafter, the pieces of fabric are taken out, oxidized in a 0.5% solution of sodium perboratc, subsequently boiled for 20 minutes in a 0.5% soap solution, then washed and dried. About 1700% more of the dyestutI is adsorbed by the piece of fabric treated with the catalyst than by the piece of fabric treated with the catalyst-free suspension.

The copper sol serving as catalyst was prepared as follows: 20 g. CuS0 .5H O are dissolved in 750 ml. H O, treated with 200 ml. .5% pearl glue solution, and subsequently reduced with 1 g. KBH, in ml. H 0.

A further possibility for the preparation of a copper sol, for instance from ammoniacal solution, is as follows: 20 g. CuS0 .5H,O are dissolved in 500 ml. 11,0 and treated with sufficient NH; solution just to redissolve the precipitate which separates at first. Then, 200 ml. of a 5% pearl glue solution are added, it is diluted to 950 ml. with water, and subsequently reduced with 1 g. KBH in ml. H30.

When in the above-mentioned suspension, the catalyst and the dyestutf are replaced by the catalysts and dyestuffs stated in the following table, the results there indicated are obtained. The comparison of the reactivity of potassium borohydride in the presence or absence of catalysts is here again made by statement of the respective amount of dyestuflf adsorbed by the piece of fabric treated with the catalyst, and this is a percentage of the amount of dyestuff which is adsorbed by the piece of fabric treated with the catalyst-free suspension. Indanthrene, which is a registered trademark, is abbreviated as Ind. in the table and elsewhere throughout this specification.

(Schultz Temperature, Excess of dyestutt on the Catalyst Dyestulf Farbstotltabellen," C. d res 7th ed.)

. Cu-8ol Ind-red brown 5 RF Vol. II, 131 At 60 10,000% more dyestufi.

Cu-Sol Ind-yellow GK Vol. I, 0. 1,220 Heated to Do.

wzggyed Cu-Sol (ammonlacal) Ind-scarlet Vol. II. p. 2,000% more dyestufl. Nl-Sol (ammonlacel) Ind.-red-brown 5RF Vol. II, p. 10,000% more dycstufl. As-Sol Ind-scarlet Vol. II, p. 100% more dyestufl. As-Sol (ammoniacal)- do Vol. II, p. Do. .Ag- Ind.-brllllant violet 313 Vol. II, p. 2,000% more d estufl'. Ag-Sol.... Ind-sear Vol. II, p. 10,000% more yestutl. Ag-Sol (ammonlacal) Ind.-brl1liantvlolet 33-- Vol. II, p. 1,000% more dyestufl'. Ag-Sol (ammonlseal) Ind-scarlet R Vol. II, p. 3,000% more dyestufl. Sn-Sol --do Vol. II, p. 30% more dyestufl'. Mo-Snl n Vol. II, p. o. Mo-Scl (ammonlacal) do V II, p. 40% more dyestufl'.

be employed in all other cases where boron compounds can be used for the reduction of organic compounds.

The following examples further illustrate the invention without, in any way, limiting it thereto.

Example I 200 ml. of a suspension containing the following compounds per liter:

Cu sol containing 0.05 gram Cu as catalyst ml 10 Indanthrene scarlet R (Schultz Farbstofitabellen,"

7th edition, vol. 2, page 132) g-.. 0.3 KBH, g 0.2 Na CO, g- 1.0 Na,SO g 12.0 NaOH (38' B.) ml 10 Example 2 Several pieces of cotton fabric are soaked in a suspension of (per liter):

which are subsequently squeezed uniformly between two rolls until the amount of liquid remaining on the fabric comprises about of the net weight of the fabric, and they are subsequently exposed to saturated steam at normal pressure. The individual pieces of fabric are steamed for periods of varying duration. Subsequently, they are oxidized in a 0.5% solution of sodium perborate, and then boiled in a 0.5% soap solution for- 20 minutes. For comparison, the same number of pieces of fabric are soakedin the above-described boiled catalyst-free suspension and further processed according to the above directions.

'ach is introduced into the two above described sus- The following result is thereby obtained: (1) The steaming period required in order to fix the piece of fabric treated with the catalyst-free suspension.

dyestutf on the piece of fabric treated with the catalyst SchultcfFarbstoflta- Exoessoidyestufl' on amounts to 45 seconds, whilst a final value is only ob- Dyesmfl f i gg gg g the ggfz gg tained after 120 seconds on the piece of fabric treated with the catalyst-free suspension.

Ind-navy blue BF. Volume II a e 202. 0007 more d estufl. (2) After a uruform period of steaming lasting 120 Ind-brown BR Suppl. voliiigage 10s. Do: y seconds, the amount of dyestuflf fixed on the piece of fabfigjgfiflg gg 1 2: 3 3gric treated with the suspension containing the catalyst is rngn a r r g nn yo nmo page g go g r, more] dy st n.

l1 .-Vl0 e 0 ume e more YES u more than the amount of dyestufi the Plece of 10 Ind.-re d violet RH Volume I, 1,354 1007:: more dyestufl. fabric treated with the catalyst-free suspension. lng-lgrrllrant violet Volume I, N2. 1,265 2,0oo% more hyestufl.

When in the above-mentioned suspension, the catalyst mdrrd RK volume 1' 358m Do. and the dyestuff are replaced by the catalysts and the lngidklrquoise blue np sg fl, Do. dygstutfisl statedbtin thie f cl lkllowing table, th? tgesults :hert'e g 5% fifii. 5N1, 1,1 i zgogg ioro dyelstuitLfl m rca are 0 arne e comparison 0 e reacrvry n o e .rmge .omore yesu of potassium borohydride with or without catalyst is in md'qcd B3B 5533 21; mm dyestuffthis case again made on the one hand by means of the 5 Volume 8E0131--- fi th abr Ind-brilliant green B. Volume I, r. 1,269... Do. Penod of Steammg l'equlred ell-her case to X e m J Ind-green GT Volume 11, page 130.-. 10,000% more dyestufl. amount of the dyestutf, and on the other hand by the -s BB g ,Xf statcmcnt of the increase in the respective amount of dye- Ind-blue BC Suppl. \gglume 11, Do.

agel stuff WhlCh after the same period of steaming is on the mtg MG SuppL Volume II, D0 piece of fabric treated with the suspension containing the page 0 catalyst, and this is a percentage of the amount of dye- Ind-'bmwn R gg g stufi which iS absorbed by the piece of fabric treated Wit Ind-olive R Volume II, page 67. Do. the catalyst-free suspension. 25

Period oi steaming for fixing equal amounts (Schultz oi dyestufl. Adsorhcd dyostur'l Catalyst Dyestuil' Fnrbstotitnhollen," amount alter equal 7th ed.) Steaming pcnods with Cu-S l o i a] Ind.- cllow GK Vol. I No. l 220 90 120 At 120 sec., 667 more. m-soifif iffli ui ImL-iil'own Vol. 11 No. 11227.- 90 240 At90see.,33% more. Ni-Sol (ammoniacal) Ind-brown Vol. I, No. 1,227 0 240 At 90 sec., 66% more. (lo-Sol Ind.-yellow3GFN ctzllraugfndrixkmdled. 45 120 At60sec., 25% more.

Example 3 Example 4 An ammoniacal Cu sol prepared as described in Exam- (a) 20 m1 of a solution containing: ple 1 rs dried by a spray drier m an atmosphere of nrtro- 40 gen. 200 ml. of a suspension containing the following potassfum dwhmmale 50 constituents per litre: potz'lsslum tomhydrlde --mg-- Cu colloid as catalyst (containing 0.05 g. Cu) -g 0.267 Sdmm w mate 265 potsslum boranate are placed in a test tube into a beaker with boiling water, carbonate ---8 0-533 taken out after 6 minutes, rapidly cooled to room temsodfllm p t perature, and added to a mixture of 100 ml. of water Sodium hydroxide solution (38 Be.) --m and 10 ml. of acetone. After 15 minutes, the solution lndamhreng pt blue RCL (Schultz Farbstoffthus obtained is treated with ml. of 4 N sulphuric acid,

tabellen, 7th edlllofl, Volume L P 1 10 ml. of 85% phosphoric acid, and a drop of a 1% soluare heated to 60 C., and 10 g. of cotton fabric are placed for 1 hour in the suspension and turned over therein from time to time. Subsequently, the piece of fabric is taken out, oxidized in a 0.5% solution of sodium pcrborate, then boiled for 20 minutes in a 0.5% soap solution, and then washed and dried.

For comparison, a second piece of fabric is treated under the same conditions with a suspension having the above stated composition but containing 1 g. of sodium carbonate per liter and no catalyst. The sample for comparison is also oxidized and after-treated as described above. Essentially more dyestuif is fixed on the piece of fabric treated with the suspension containing the catalyst than on the piece of fabric treated with the catalyst-free suspension.

10,000% more dyestuif are adsorbed by the piece of fabric treated with the catalyst than by the piece of fabric treated with the catalyst-free suspension.

When in the foregoing suspension, the dyestulf is replaced by the dyestufis specified in the following table, the results there reported are obtained. The comparison of the reactivity of potassium borohydride in the presence or absence of catalyst is in this case again made by statement of the respective amount of dyestulf which is adsorbed by the piece of fabric treated with the catalyst, and this is a percentage of the dyestufi which is adsorbed by the tion of diphenylamine sulphate, and then the unreduced potassium bichromate is determined by potentiometric titration against a standard l/l0 molar FeCl, solution.

It is found that within the limits of experimental error of 11% no Cr+ was reduced to Cr.

(b) However, when there is added to the above reaction mixture of borohydride and bichromate 2 ml. of an ammoniacal Cu sol, prepared as described in Example 1 and containing 0.01 g. of Cu, 44.2% of the Cr are now reduced to Cr under the same conditions as above.

(c) A similar effect is obtained when use is made as catalyst of an ammoniacal Ag sol prepared by analogy to the Cu sol but using 0.314 g. of potassium borohydride on 7.9 g. of silver nitrate (0.015 g. Ag). Under the same conditions as above, 23.5% Cr is reduced to Cr.

(d) When there is added to the above react-ion mixture of borohydride and bichromate a catalyst comprising 5 mg. of CuSO; and 10 mg. of ethylene diamine, 44.2% of the Cr is reduced to G under the same conditions as above.

(e) However, if 10 mg. K [Ni(CN) are added to the above reaction mixture of boranate and bichromate as catalyst, 10% of the Cr+ are reduced to Q under the same conditions as above.

(f) However, if 5 mg. of sodium anthraquinone-Z- sulphonate are added to the above reaction mixture of borohydride and bichromate as catalyst, 61% of the Cr+ is reduced to Cr under the same conditions as above. When use is made as catalyst of 5 mg. or the stated amount of the substances listed in the table below, the

following reduction data are obtained:

Percent of the Cr Catalyst: reduced to Cr Sodium-anthraquinone-2-sulphonate 61 Potassium-anthraquinone-l-sulphonate 45 Potassium-1-nitro-anthraquinone-8-sulphonate 22 1,5-diamino-anthraquinone-Z-sulphonic acid 11 I 1-amino-anthraquinone-2-sulphonic acid 31 1-amino-anthraquinone-8-sulphonic acid 34 1-amino-anthraquinone-3-sulphonic acid 37 3-amino-ant-hraquinone-2-carboxylic acid 4l Sodium-1-nitro-anthraquinone-6-sulphonate 24 l,4,5-trihydroxy-anthraquinone-Z,6-disulphonic acid 9 Potassium-1-nitro-anthraquinone-5-sulphonate 13 l-nitro-anthraquinone-7-sulfonic acid 26 1,2,4-trihydroxy-anthraquinone-3-sulfonic acid 22 4-bromo-3-amino-anthraquinone-2carboxylic acid 41 Sodium-4,8-dibromo-l,S-diamino-anthraquinone- 2,6-disulfonate 2 'Sodium-4-bromo-1-amino-anthraquinone-2- sulfonate 36 l-amino-anthraquinone-4-sultonic acid 14 1,4-diamino-anthraquinone-2,6-disulfonic acid 9 1-hydroxy-anthraquinone-Z-sulfonic acid 33 1,2,4-trihydroxy-anthraquinone-8-sulfonic acid 28 1-amino-anthraquinone-7-sulfonic acid 34 1-benzoylamino-anthraquinone-S-sulfonic acid 5'6 1,2 diamino-anthraquinone-3-sulfonic acid 18 1-chloro-4-amino-amhraquinone-8-sulfonic acid 16 l-methylamido-anthraquinone-6-sulfonic acid 28 Sodium-l,4-dihydroxy-anthraquinone-Z- sulfonate 20 1-amino-anthraquinone-2-carboxylic acid 31 (1,1')-dianthrimido-(4,4)-disulfonic acid 23 20 mg./l.(+)cysteinhydrochloride 2 obtained in the presence of the catalysts.

Example 5 (a) 25 ml. of a solution containing 10 mg of. potassium boranate and 5 mg. of methyl orange in a test tube are placed in a beaker with boiling water. After 20 minutes, the solution has hardly decolorised, i.e. less than 10% of the methyl orange has been reduced.

(b) However, if 0.1m]. of an ammoniacal Cu sol (0.5 mg. Cu content) is added as catalyst to the above solution and the experiment is repeated, the solution is decolourised after 70 seconds, corresponding to complete reduction of the methyl orange.

If 1 mg. of copper sulphate and 2.10- mg. of aminoacetic acid and 4 mg. of sodium hydroxide are added to the above solution and the experiment is repeated, the solution is decolourised after 60 seconds, corresponding to complete reduction of the methyl orange.

(d) If, however, 0.1 mg. K,[Ni(CN) is added as catalyst to the above solution and the experiment is repeated, the solution is decolourised after 135 seconds, corresponding to complete reduction of the methyl orange.

(e) If 0.1 mg. sodium anthraquinone-1,2-dicarboxylate is added as catalyst to the above solution and the experiment is repeated, the solution is decolourised after min- Catalyst solution (containing 0.1 g. CuCl +5 ml.

NH .CH .CH .OH) -m1 50 Indanthrene brown R (Schultz Farbstofftabellen,

7th edition, volume I, No. 1227) g l KBH, g 0.3 Nam- (38 B.) --ml 17.5

are warmed to 75 C. After 20 minutes, it is clearly evident that the major portion of the dyestuif has been reduced. For comparison, 200 ml. of a corresponding but catalyst-free suspension are also warmed to 75 C. No recognizable reduction of the dyestuff occurs even after one hour in this case. For better comparison of the two suspensions and to recognize the activity of the catalyst, a 10 g. cotton skein is introduced into each of the two above-described suspensions and left therein at 75 C. for 20 minutes whilst the skeins are turned in the suspensions from time to time. Thereupon, the skeins are taken out, oxidized in a 05% solution of sodium perborate, then boiled for 20 minutes in a 0.5% soap solution, washed, and dried. Over 10,000% more of the dyestutf are fixed 0n the skein treated with the catalyst than there is on the skein treated with the catalyst-free suspension.

(b) By the same method, use of Indanthrene blue RS (Schultz Farbstotftabellen, 7th edition, volume I, No. 1228) and of Indanthrene Red F 33 (German patent specification 825,111, Example 4) leads to the fixing of 2000% more dyestuff.

(c) When use is made during the process described under 1(a) of 50 ml. of a catalyst solution containing 0.1

gram of NiCl +5 ml. NH .CH .CH OH and 0.5 gram of potassium boranate, 2000% more dyestufi are fixed on the fiber by use of the suspension containing catalyst than by use of the catalyst-free suspension.

(d) 200 ml. of a solution containing the following compounds per liter:

SbOKC4H4O AH3O g KBH. g 0.5 NaOH (38 B.) mL- 17.5

are heated to 60 C., and only then 0.2 gram of Indanthrene green 46 (German Patent No. 661,152, Example 8, line 51) are added. The dyeing process described in Example 6(a) is then carried out with this suspension. By use of the suspension containing the catalyst, 2000% more dyestufi are fixed on the fiber than by use of the catalyst-free suspension.

Example 7 (a) 200 ml. of a suspension containing the following compounds per liter:

Catalyst solution (containing 0.1 g. CoCl +5 ml.

of NH CH,.CH NH,) ml 50 Indanthrene brilliant pink BL (Schultz Farbstofitabellen, German Patent No. 639,732, Example 4) g l KBH; g 0.5

sboKc,H,o,. /=H,0 g 0.25

Indanthrene green 4G (German Patent No. 661,152,

Example 8, line 51) g 0.6 0.5

KBH4 g are first heated to 45 C., then 3.5 ml. of sodium hydroxide solution (38 B.) are added, it is heated further to 60 C., and then the dyeing process described in Example 6(a) is carried out. By use ofthe suspension containing the catalyst, 1500% more of the dyestutf are fixed on the fiber than by use of the catalyst-free suspensron.

Example 8 A suspension containing mg. of potassium boranate, 5 mg. of Indanthrene brilliant green. B (Schultz Farbstofftabellen, 7th edition, volume I, No. .1269) or 5 mg. of Indanthrene orange RRTS (Schultz FFarbstoiftabellen, 7th edition, volume II, page 131) and 20mg. of sodium hydroxide in ml. of water is placed in a test tube into a beaker with boiling water. It was then ohserved which percentage portion of the dyestufi had bethe suspension complete or nearly comp elfiwyatting had already taken place for both dyestuffs within a short time. The following combinations were employed as catalysts:

, ,Yatted Complex forming agent Metal salt Dyestufl witliirin,

Amino acetic acid NiCh.6lhO Ind. orange 4' RRTS (Schultz Farbstotl- Ethylcnedinminc Sorbitol Ethylcne-bis-(imino-diacctic acid. Salicylic acid. Pyrocatccho] lien zocuprol lyrogallol.--

Mannitoh.

Sorbitol Aminoacctlc acid. Diacetyldioxime. Ethylenediamine lyrog lo Ethylenc-his-(iininooctic acid).

N annitol Diaoetyldioxime Salicylic acid Arninoacctic acid 6,5'mg. Scignette salt.

Ethylcne-bis- (iminodiacctic acid).

maca c111 1 mg. FcClz.

Diacetyldioxime Ethylenediamine. Sorbitol Cu-complex with p ethylene iminebiguanidene (ci. DBP 954,686).

Example 9 (a) 200 ml. of a suspension containing per litre:

Indanthrene scarlet R (Schultz Farbstofitabellen, 7th edition, volume ll, page 132) g Na cO g and Na SO g 25.0

are warmed to 50 C. After 10 minutes, it is clearly evident that the major portion of the dyestufi has been reduced. For comparison 200 ml. of a corresponding suspension which contains no catalyst but otherwise equal amounts of the same constituents are also heated to 50 C. In this case, reduction of the dyestulf only starts after 45 minutes and to an immaterial extent. For better comparison of the two suspensions and to recognize the activity of the catalyst, a 10 g. piece of cotton fabric is introduced into each of the two above described suspensions and left therein at 50 C. for about 1 hour, whilst the pieces of fabric are turned in the suspensions from time to time. Thereafter, the pieces of fabric are taken out, oxidised in a 0.5% solution of sodium perborate, boiled for 20 minutes in a 0.5% soap solution, then washed and dried. Essentially more of the employed dye- V slyfiis now fixed on the piece of fabric which was treated in the suspension containing the catalyst than on the piece of fabric which was treated with the catalyst-free suspension. About 1700% more of the dyestuif is absorbed by the piece of fabric treated with the suspension containing the catalyst then by the piece of fabric treated with the catalyst-free suspension. .7

- --(-b) Duringth e process described under (a), use is made of K [Ni(CN) g 0.2

and Indanthrene brilliant violet RK (Schultz Farbstofftabellen, 7th edition, volume I, No. 1223) g 1 g in place of the catalyst and dyestufi.

, Dyeing is then carried out by the method described under (a). In this case, however, between the oxidising and soap bath, the piece of fabric was introduced into a 1% solution of acetic acid at C. for 5 minutes. 400% more of the dyestufi was fixed on the fabric treated with the suspension containing the catalyst.

(c) When use is made during the process described under (a) of 200 ml. of a suspension containing per litre:

Sodium 1-amino-4-bromo-anthraquinone-2 sulphonate g 1.3

Indanthrene-blue RS (Schultz Farbstoiftabellen," 7th edition volume I, No.1228) g 2.0

KBH g 2.0

N32C03 g 6.7

and

NaOH (38 B.) ..ml.. 8.0

dyeings are obtained whereby the piece of fabric treated with the suspension containing the catalyst contains about 900% more dyestutf than the piece of fabric treated with the catalyst-free suspension.

Example 10 Indanthrene navy blue TRF --g-.. 8 RBI-I g 6 Na CO; g 20 and are subsequently squeezed uniformly between 2 roll:

12 portion of the dyestufi had become vatted after what time. It was found that the dyestutf was almost completely vatted only after 10 minutes.

However, if 25 mg. of 3-amino-anthraquinone-2-carboxylic acid were added to the suspension, the dyestuif had already been vatted after 4 minutes.

Corresponding results are obtained if instead of the potassium boranate there are used 7 mg. of dimethyl borazane or 6.2 mg. of diborazyl. If there is used a less alkaline medium there can be used also N-methyi of sodium hydroxide is placed in a test tube into a beaker with boiling water. It was then observed what percentage 7 005 until the amount of liquid remaining on the fabric comprises about 85% of the net weight of the fabric; therebomzane or N'mmithyl Immune after, they are exposed to saturated steam at normal pres- The stated amounts of the following 'f F can sure. The individual pieces of fabric are steamed for firth as catalysts f' observatloms made periods of varying duration. subscquemly, they are of the times stated in the table which are required for the oxidized in a 0.5% solution of sodium perborate and P P boiled for minutes in a 0.5% soap solution. For v atting time, comparison, the same number of pieces of fabric are Catalyst in minutes introduced into a suspension which except for the catalyst 5 Ascorbic acid 6 has the same composition as that described above, and are 0.5 Glucose 7 further processed according to the above directions. The 20 0.25 Benz0quinone-(1,4) 6 following has been established: 3-: 32 2 g (1) The period of steaming which is required to fix the dyestufi on the piece of fabric treated with the sus. 3-: 2'g:gfigfggfiggga:$323 3 pension containing the catalyst amounts to 60 seconds, DMQMDMMLM 5,) kemne whilst it amounts to 240 seconds fQl' m P of fabric 20 0.25 Potnssium-naplitl'ioquinone-(1,2)-4-sulfonate 2.5 treated with the catalyst-free suspension. 0.2 Sodlum-diplienylaminei-sult'onate 7 (2) For equal periods 01' steaming lasting for 120 sec- 0.25 N(2'-hydroxyphenyl)-2-hydroxy-naphthoquinoneonds, the amount of dycstutf fixed on the piece of fabric (LU- 4 6 i 0.25 2-cliloro-3-amino-napiithoqulnone-(1,4) 2 treated with the suspension containing the catalyst s more than the amount of dyestuflf on the piece of fabric 30 N *Plmwqulmne (114) 3 treated with the catalyst-free suspension.

. N h l If the catalyst and the dyestuff in the above-mentioned g3: gg gggggg (1 2) 4 sulphomc add g suspension is replaced by the catalyst and dyestuffs listed 0 25 pymcatechol 6 in the following table, the results thereindlcamd are 0b- 3? 0.25 2,4-tri-anilino-authruquinone-(1) 5 tained. The comparison Of the reactivity Of boranate 0 0.25 Pheuyl-rlng-sulphouated 4-(mchloroanillno)-N- with and without catalyst is in this case again made, on thyl-(1,9)-anthrnpyridone 6 one hand, by h period f stcaming i d i i h 0.2 4=,4 ,4'triamino-trlphenylmethante-hydrochloride 8 case to fix the major amount of the dyestuif, and, on the 3- i2'2?fg f a f g g 7 other hand by flames the mass in 4 0'25 s';a1;...'1 2233i;d12133231131..gfilniifiiiffl; 6 tive amount of dyestuff which after equal periods of steammm p 5 25 ing remains on the piece of fabric treated with the cata- 025 mm uiuoncq-suiphonic acid 6 lsyt, and vthis as a percentage of the amount f dyestuff 0.25 2-umino-uuthrnquinone-3-sulphonic acid 5 which is absorbed by the piece Of fabric treated with the 0.25 Sodium-3-nmino-4-bromo-nnthraquinone-Z-carboxcatalyst-free suspension. y e 4 Steaming period for fixing equal amounts oi dyestui! Schultz "Farbstoi'i- Adsorhcd dyestufl amount Catalyst Dyestufl tabellen, 7th edition alter equal steaming peri- Without ods with catalyst With catalyst, sec. catalyst,

sec.

3 .11. K4C0(CN)| Ind.-red F313 (Germ. Patent 240 360 At 240 see, 67% more.

' $25,111 Example 3 g./l. K Co(CN)| Ind-brilliant violet 313.-.. VohII, p. 128 90 240 At 240 sec., 25% more. 0.6 g./l. K C0(CN) lndanthi' lr iiaahrilllaut Vol. II, p. 128 00 240 At 120 sec., 67% more.

green 2 g.ll. Na,Sn(OH) Ind.-blue RS 240 At 120 sec., more. 1 g./l. Na,Sn(OH) Ind-blue RS" 240 At 120 sec, 67% more. 3 g./l. sodi in 0-4- Ind.blue RS. 300 At 120 see, 400% more.

thraquinone-2-sulphona 3 gll ifdiiiydrgxy-anthraquinonc- Ind-golden yellow RK... compared with..- 300 Do.

-a p oncac 3 1,2,5,8-tetrahydroxy-anthra- Ind.-olive-green B Vol. II, p. 131 120 compared with.. 240 At 240 sec., 15% more.

q no e. 3 lk s o gium anthraquinone-Z- Ind-yellow GK Vol.1, No.1,220. 45 compared with..- 240 At 240 $00,, 150% more. 3 n 8 sogli1llr1im;zmino-anthraqul- Ind. brilliant blue 30.... Vol. II, p. 128 30 compared with... 90 At 120 sec., more.

5 3 g./l. l-arn no-anthraquinonc-Zi-sul- Ind-green GG Vol. II, p. 130 00 compared with... 300 At 240 sec. 900% more.

phonic acid. 3 gi l. sg iigm d-am ino-tbromo- Ind-red RK Vol. I, No. 1,258....- 90 compared with..- 300 At 240 sec., 100% more.

q n ne- S11 0118 3 gJl.1,2'dihydr0Xy-an thraquin0ne" Ind-brilliant violet 38.... Vol. II, p. 128 45 compared with..- 300 At see, 400% more.

Example 12 70 0.25 (1,1')-dianthrimide-(4,4)-diaulphonic acid 7 0.25 l-benzoyiamiuo-anthraqulnone-b-aulphouic acid 7 A suspenslon comalmng 5 of potassumf hora-Date 0.25 Sodium-l-nitroanthraquinone-Z-carboxylate 5 5 mg. of Indanthrene orange RRTS (Schultz FaibStOlf- 0.25 Potassium-1-bromo-anthraqulnone-B-sulphonate 5.5 tabeucn," 7th cdltlon, Volume II, page 131) and 300 mg. 0.25 8-bromo-5-amino-1-methoxy-acetylnmiuo-antiiraquinone 5. 1,2,7-tri-l1ydroxy-nnthraquinone Vatting time, CataiystContinued in minutes 1,3,5,7-tetra-hydrxy-anthraqulnone 6 Sodium-anthraquinone-1,8-disulphonate 4.5 Sodium-anthraquinane-1,3,5,8-tetra-sulphonate 6.5 Sodium-1,4-dichloro-anthraquinone-G-sulphonate 4 1,5-di-o-anthranilido-anthraquinone Anthraqulnone-2-carboxylic acid 4.5 Sodium-1,5,7-tri-ch1oro-8-amino-anthraquinone-3- sulphonatc 5 l-nltro-anthraquinone-fi-sulphonic acid 5 l-nitro-authraquinone-7-sulphonic acid 5 Potassium-l-nitro-anthraquinoue-5sulphonate 6.5 Potasslum-l-nitro-authraquinone-8sulphonate 4.25 Potassium-anthraquinoue-l-sulphonate 4 Sodium-anthraquinone-2-sulphonate 5 1,2,5,8-tetra-hydroxo-anthraquinone 5.5 1-amino-4-bromo-anthraquinone-Z-sulphonic acid 7 1-nmino-2-methyl-anthraquinone 7.5 1,5-diamino-4,8-dibromo-anthraquinone-2,6-disu1- phonic acid 5.25 1,5-diamlno-anthraquinone-2-sulphonic acid 7 1-:1mino-anthraquinone-fZ-sulphonic acid 5 1-amino-anthraquinone-S-sulphonic acid 6 1-amino-nnthraquinone-S-sulphonic acid 6 Sodlum-1-chloro-2-amino-anthraquinoae-Ei-suiphonate 3 l-p-toluidcranthraquinone-S-sulphonic acid 6.25 1,2-dihydroxymnthraquinone-8-sulphonic acid 7 Potassium-1,4-diliydroxy-anthraquinone-6-sulphonate 7 1,4-dihydroxy-anthraquinone-2,6-disulphonic acid 6 4-amino-1-anilido-anthraquinoue-3-sulphonlc acid 1,4-diamino-anthraquinone 7.5 2-amino-anthraquinone 6.5 1-chloro-2 amino-anthraquinone 5 2-chloroanthraquinone 7.5 l-chloro-anthraquinone 8 Di-a.-anthraquinoyidisuiphidc 8 Anthraquinonc 7.5 Anthrone 7 1-nitro-4chloro'anthraquin0nc-5-sulphonic acid 6.5 l-iodo-anthraquinone 7 Anthraquinoue-1,5-dicarhoxylic acid 5 Anthraquinonel,4-dicarhoxyiic acid 8.25 1,5-dichloro-anthraqulnonc-l-carboxylic acid 3.5 l-ethanolamino-anthraqulnone 7 2-p-benzoylchiorldo-anthraquinone 7 1-nitro-2,4-dlhydroxy-anthraquinone 5 1,4-diamino-2-chlorofi-hydroxo-anthraquinone 8 l-amino-3A'dihromo-anthraquinone sulphonic acid 4 1,4,5-triamino-anthraquinone G 1-amino-2-methyl-4-nitro-anthraqninone 7.5 1-phenyl-1-carboxy-2-(anthraquin0nyl-2)- ethane 5 1,4-dihexamethylenediamino-anthraquinone 7 1 amin0-2qnethyl-S-chlorcranthraquinone 7 Anthraquinonyl l-aidehyde 5 Ihthaloylisatoic acid anhydride 5.5 1-amlao-anthraquinone-2-carboxylic acid nitrile 7 1,5-dichloroanthraquin0ne-2,6 dicarboxylic acid 3 1,8-dlchloro-antliraquiaone-2-earboxyllc acid 0 1-amino-8-chioro-anthraqnlnone-carboxylic acid 6 Anthraquinonel,2-dlcarboxylic acid G 1,2-di-(o-hydroxy-aniiino) anthraquinone G Sodlum-1-hydroxy-4-nitro-anthraquinonc-2-sulphonate 3 1,4-di-(2'snlphonic acid-4-methyl)-anthraquinone 6 4,4-dlamlno-1,1'-dlanthrlnido-2,2-dlsulphonic acid 7 1,4 diamino-2,3-dichloro-anthraquinone-5-sulphonic acid 7 1-amino-4-(4-methyl-2-sulplmnic acid-anthrathraquinone2-sulphonic acid 5 Sodium-1,2-dihydroxo-anthraquinone-fi-sulphonate 7 1,5-dimethanolamino-4,8-dlhydroxy-anthraquinone-Zi-sulphnnlc acid 8 4 ,4-dihydrow-3 ,341imethyl-trlphenyl-methanedicarboxylic acid-(5,5) 8

Vatting time,

Mg. Catalyst-Continued in minutes 0.2 -n1tro-4 ,4-dl(N-lilimethylamintrti-iphenylmethane) I 8 0.25 N-methyl-l,Q-pyrazoloneanthrone-2-carboxylic acid 0.25 N-methyi-l,Q-pyramleanthrone-2-carboxylic acid-4-sulphonic acid 8 0.2 1,9-thiazoleanthrone-2-carboxylic acid-chloride 5.5 0.2 1,9-anthrapyrimidine-2-carboxylic acid 7 0.12 1,4,9,10-anthradiquinone 5 0.25 Leuc0-1.4-dihydroxy-anthraquinone 2 0.25 Leuco-l,4-diamino-anthraqulnone 3.25 0.25 Leuco-l,2,5,B-tetrahydroxy-anthraquinone 6.5 0.2 Leuc 5,8-dioxaethylamino-1,4-dihydroxy-anthraquiuone 7 0.25 Leuco-1,4-dihydroxy-authraquinone 1 Example 13 1200 ml. of an aqueous solution containing 0.75 g. of sodium hydroxide per litre are first saturated with oxygen, then 0.4 g. of potassium boranate are added, and brought to reaction with 100 ml. of oxygen in a sealed vessel, with stirring. After a reaction time of 45 minutes, an oxygen determination was carried out on the gas present above the solution. It was found that 4.9% of the oxygen has been reduced by the boranate. If, however, 0.3 g. of sodium anthraquinOne-Z-sulphonate were added to the solution as catalyst, and the experiment was repeated with further 100 ml. of oxygen, 99.2% of the oxygen were reduced by the boranate within 45 minutes.

A similar effect, i.e. a reduction of 99.8% of the original 100 ml. of oxygen within 45 minutes, is attained by the same procedure with 0.3 g. of anthraquinone- 2-carboxylic acid as catalyst.

Example 14 is stirred into an aqueous vat dye suspension which contains l5 g./litre of Indanthrene red F 3 B (German patent specification 825,111, Example 4). A cotton web is foularded and steamed by a continuous process using this bath at 25 C. and an apparatus described by F. Weiss in Die Kiipenfarbstoflfe, 1953, page 201. The amount of liquid remaining on the fabric comprises about 70% of the weight of the fabric. The speed of passing the goods amounts to 60 m./min., the stay in the steaming apparatus about seconds. After leaving the steamer, the web passes as usual a roller vat system for rinsing, oxidising, and soaping. A bright blue red dyeing is obtained.

In place of the Indanthrene red F 3 B, the following dyestuffs may also be employed:

Indanthrene scarlet R (Schultz Farbstofftabellen," 7th edition, volume II, page 132) Indanthrene blue 5 G (Schultz Farbstoiftabellen, 7th

edition, volume I, No. 1238) Indanthrene red-brown SRF (Schultz Farbstolftabellen,"

7th edition, volume II, page 131) Example 15 In an apparatus such as is mentioned by F. Weiss in Die Kiipenfarbstofie, 1953, page 218, a cotton yarn cheese is dyed at a ratio of goods weight to bath weight of 1:10 in such a manner that a dyestufl suspension containing per litre of liquor 3 g. Indanthrene blue 5 G (Schultz Farbstofitabellen, 7th edition, volume I, No. 1238) which is divided as finely as possible is circulated 15 at 25' C. Then, there is added, at the rate of 2 g./l., a mixture consisting of:

Percent KBH 20 Nagcog Na SO 8 NaHCO, 5 K (CN), 1-amino-4-bromo-anthraquinone-2-sulphonic acid 6 and p-naphtho] 6 and the dye liquor is allowed to circulate for 45 minutes, with heating to 70 C. Subsequently, it is thoroughly rinsed with cold water, oxidised with 2 g. of sodium perborate per litre, and soaped with boiling. A blue dyeing is obtained.

Example 16 A piece of cotton fabric is soaked in a suspension containing per litre 20 g. of Indanthrene brilliant green FFB (Schultz Farbstofitabellen," 7th edition, volume II, page 128), 6 g. of potassium boranate, and 22 g. of sodium carbonate which is thereupon squeezed uniformly between two rolls until the amount of liquid remaining on the fabric comprises about 85% of the net weight of the fabric; it is subsequently exposed for 1 minute to saturated steam at normal pressure, and then oxidised in a 0.5% solution of sodium perborate and thereafter boiled for 20 minutes in a 0.5% soap solution. A green dyeing is obtained.

If the same dyeing is carried out with a suspension containing a catalyst, the dyeing becomes deeper. If, for example, 2 g./l., of sodium anthraquinone-Z-sulphonate are added to the suspension, the dyeing is 80% deeper than that without catalyst; or if 2 g./l., of K [Co- (CN)s] are added as catalyst, the dyeing is 200% deeper.

However, the catalyst activity is essentially more intense, when both catalysts are added simultaneously and in equal parts, and in fact half the amounts stated above so that the suspension again contains a total of 2 g./l. of catalysts. The dyeing is now 400% deeper than that from the suspension without the catalyst.

Example 17 25 ml. of a suspension containing 5 mg. of Indanthrene yellow GK (Schultz Farbstofitabellen, 7th edition, volume I, No. 1241), 5mg. of potassium boranate, 300 mg. of sodium hydroxide, and one of the following catalyst combinations, are placed in a test tube into a beaker with boiling water, and it is observed after what time and to what extent vatting takes place. The catalyst combinations employed are: (a) 0.1 ml. of a copper sol containing 0.5 mg. of copper, and 0.25 mg. of sodium anthraquinone-Z-sulphonate; (b) 0.1 ml. of a copper sol containing 0.5 mg. of copper, and 0.05 mg. of 1,2-diamino-anthraquinone-3-sulphonic acid.

Thereby, the following observations are made: By use of the catalyst mixture (a), there is 40% vatting within 7 minutes, and by use of the catalyst mixture (b), there is 100% vatting within 6 minutes.

The copper sol serving as catalyst is prepared by dissolving 20 of CuSO -5H,O in 500 ml. of water, and treating with sufficient conc. ammonium hydroxide solution just to redissolve the precipitate which separates at first. Then, 200 ml. of a 5% solution of pearl glue are added, the mixture made up with water to 950 ml., and the copper salt is subsequently reduced with 1 g. potassium boranate in 50 ml. of water.

Example 18 g. of copper sulphate, 2 g. of aminoacetic acid, and 4 g. of sodium hydroxide, (b) 0.25 mg. of sodium anthraquinone-2-sulphonate, and (c) 0.05 mg. of quinizarine, are placed in a test tube into a beaker with boiling water, and it is observed after what time and to which extent vatting takes place. After 4 minutes, 50% of the dyestuif have been vatted.

(b) When use is made of a catalyst mixture comprising 0.083 mg. each of K [Co( CN),], quinizarineyand sodium anthraquinone-2-su1fonate, 15% of the dyestutf have been vatted after 9 minutes.

(0) When'use is made of a catalyst mixture comprising 0.05 mg. each of sodium anthraquinone-Z-sulfonate and quinizarine, 10% of the dyestufi have been vatted after 10 minutes.

(d) When use is made of a catalyst mixture comprising 0.05 mg. of anthraquinone-l,2-dicarboxylic acid and 25 mg. of potassium 1-nitro-anthraquinone-8-sulfonate, 90% of the dyestuflf have been vatted within 9 minutes.

Example 19 25 ml. of solution containing 10 mg. of potassium boranate or 6.8 mg. of sodium boranate, and 5 mg. of methyl orange are placed in a test tube into a beaker with boiling water. After 15 minutes, the solution has not decolorized, i.e. less than 5% of the methyl orange have been reduced.

The reduction proceeds somewhat faster, i.e. 30% within 12 minutes, when under the same experimental conditions 0.05 mg'. of 1,2,9,10-tetraoxoanthracene are added.

However, the reduction takes place much faster when the following catalyst mixtures are employed: (a) 0.25 mg. of 2,5-7-(N-dimethylamino)-propylamino-1,4-benzoquinone and 0.05 mg. of 1,2,9,10-tetraoxoanthraquinone. 50% reduction takes place within 7 minutes, or (b) 0.20 mg. of potassium 1-nitro-anthraquinone-Z-sulfonate and 0.05 mg. of 1,2,9,10-tetraoxoanthraquinone. reduction takes place within 7 minutes.

Similar results are obtained if instead of the alkali metal boranate there are used 14.4 mg. of dimethyl borazane or 18.9 mg. of visopropyl borazane or 12.5 mg. of diborazyl.

Example 20 131), 20.5 g. of sodium carbonate, and 7.5 g. of diborazyl or 11.3 g. of isopropylborazane, which is thereupon squeezed uniformly between two rolls until the amount of liquid remaining on the fabric comprises about of the net weight of the fabric. Subsequently, it is exposed to saturated steam at normal pressure. Thereupon, it is oxidized in a 0.5% solution of sodium perborate and boiled for 20 minutes in a 0.5% soap solution, washed, and dried. An orange dyeing is obtained.

When 1 g. per liter of sodium anthraquinone-Z-sulfonate and 1 gram per liter of K [C0(CN)e] are also added as catalysts to the above suspension, with otherwise the same experimental conditions, the dyeing becomes 10 times more intense in the case of diborazyl and 3 times more intense in the case of isopropylborazane.

The same experiment can also be carried out with other vat dyestuffs, e.g. Indanthrene brilliant green FFB (Schultz Farbstofitabellen," 7th edition, volume H, page 128).

17 are placed in a test tube into a beaker with boiling water, and it is observed after what time and to which extent vatting takes place.

90% of the dyestulf have become vatted after 7 minutes.

If 7 mg. of dimethyl borazane are added to the suspension in place of the 5 mg. of potassium boranate, 90% vatting already takes place after 5 minutes; if 6.2 mg. of diborazyl are added to the above suspension in place of the 5 mg. of potassium boranate, 90% of the dyestuff have already become vatted after 4 minutes.

Example 22 borazane, and 0.25 mg. of K [Ni(CN) are placed in 1 a test tube into a beaker with boiling water. After 4 /2 minutes, the solution has become decolorized corresponding to complete reduction of the methyl orange.

If the dimethyl borazane is replaced by 12.5 mg. of diborazyl, 50% of the methyl orange are reduced after 10 minutes.

Example 23 A solution containing 20 g. of nitrosodimethyl amine, 80 ml. of water, 5 ml. of a 45% sodium hydroxide solution and 5.15 g. of sodium boranate are heated at 100 C. under reflux for about 5 hours. Subsequently to the reaction mixture there are added 150 ml. of a 45% sodium hydroxide solution and the mixture is then subjected to a steam distillation. The distillate obtained is boiled with diluted sulfuric acid, and upon addition of sodiumbicarbonate there is analyzed by an iodometrical analysis the content of the asymmetrical dimethyl hydrazine. The content is about 0.4% of the theoretical.

If the heating under reflux of the above reaction mixtures is carried out in the presence of one of the following catalysts the following yields are obtained:

. Yield in Catalyst: percent 5 ml. of an ammoniacal copper sol complex compound consisting of l g. of amino acetic acid 13.1

and 0.5 g. of CuCl 29 1 g. K [Ni(CN) 51.9 Plus 10 ml. of a 1% pearl glue solution.

Example 24 25 ml. of a solution containing 10 mg. of ammonium sulfate and 5 mg. of Sirius light orange 3 GLD are reacted with 5 mg. of potassium boranate and 3.5 mg. of sodium boranate and it is observed after What time the dyestuff is decolorized, that means reduced. After a period of 600 seconds decolorizing takes place only to less than 5%. If to the reaction mixture there are added 0.01 ml. of an ammoniacal cuprous sol containing 0.05 mg. of copper, the reaction mixture is completely decolorized within 90 seconds.

A similar result can be obtained with the dyestuffs indicated in the following table:

Schultz Farb- Reduction Dyestutl stofitabellen,"

7th edition Without catalyst With catalyst Sirius blue FG- Suppl. vol. I, Alter 600 sec., After 80 sec.,

page 130. 5%. 100%. Sirius black L Suppl. vol. I, do After 600 sec.,

page 132. 50 Sirius grey GB. Suppl. vol. I, do After 45 sec.,

page 130. l Sirius green G Suppl. vol. I, -do Do.

page 131. Sirius light d0I ..d0 D0.

green BB. Sirius light do do After 50 sec.,

grey GG. 100%. Sirius light do do After 45 sec.,

bluc BRR. 100%. Sirius grcy G.-. Suppl. vol. I, do Attcr C0 scc.,

page 130. 100%.

Similar results are obtained by using instead of the copper sol the following catalysts:

(a) 0.5 mg. of K [Ni(CN) (b) 0.5 ml. of a solution containing per liter 1 g. of copper sulfate, 2 g. of amino acetic acid and 50 ml. of 2 n-sodium hydroxide solution (c) 0.25 mg. of anthraquinone-Z-sulfonic acid (d) a mixture consisting of 0.125 mg. of K [Ni(CN) and 0.125 mg. of anthraquinone-Z-sulfonic acid.

Example 25 10 g. of a cotton fabric are dyed at 85 C. for 20 minutes from a solution containing 2 g. of Sirius light orange 3 GLD and 10 g. per liter of sodium sulfate. The dyeing is rinsed and dried. A small piece of this dyed cotton fabric is completely soaked with a solution containing per liter 10 g. of sodium carbonate, 20 g. of potassium boranate and 1.25 g. of sodium hydroxide. Thereafter the cotton fabric is treated for 60 seconds in a stream of steam and is then rinsed with a 1% acetic acid solution, then 5 minutes treated with water and subsequently dried. The dyeing on the cotton fabric is now bleached to less than 10%. Its color is brownish-red.

If to the boranate solution there are added as catalysts per liter 0.1 g. of CuSO and 0.5 g. per liter amino acetic acid the dyeing is bleached to 50% within 60 seconds. A similar result is obtained with cotton fabrics which are dyed in the same manner as indicated above with the dyestuffs of the following table. The table indicates also to which extent the dyeings are bleached if the catalyst is added to the boranate solution:

Schultz Fsrb- Reduction Dyestufl stotltabcllcn,"

7th edition Without catalyst With catalyst Sirius black L. Suppl. vol. 1, After 00 sec., Alter 0 see,

page 132. 50% brown. 85% brown. Sirius grccn G Suppl. vol. 1, After 60 sec., After 60 scc., pa e 131. 50% green. 60% green. Sirius light do After 60 $00., After 60 soc., blue BRR. 5% blue. 25% blue. Sirius blue FG- Suppl. vol. 1, After 60 sec., After 60 scc.,

page 130. 50% blue. blue.

A similar result is obtained if instead of the above catalyst there are used the following compounds:

If the above mentioned catalyst mixtures are used, a better result is obtained as by using the same amount of a copper being part of the mixture.

Instead of the potassium boranate there can be used also as reduction agent N-methyl borazane or N-trimethyl borazane in a solution containing ammonium sulfate.

Example 26 A mixture consisting of 24 g. of nitrobenzene, 7.5 g. of sodium boranate and 5 ml. of a 45 sodium hydroxide solution is heated to 160 for 2 hours. The reaction product is subjected to a steam distillation. Thereby 65% of the nitrobenzene are recovered. Azoxybenzene is obtained with a yield of 15% of the theoretical besides small amounts of azo benzene.

If the reducing process is carried out in the presence violent reaction takes place at about C. The reactheoretical referred to the reacted nitrobenzene.

If there is used as catalyst 1 g. of K,[Ni(CN) or 0.5 g. of the sodium salt of anthiaquinonc-Z-sulfonic acid there is obtained azo benzene besides a small amount of azoxybenzol. Yield in the case of the K [Ni(CN) 70% and in the case of the anthraquinone sulfonic acid 42% referred to the reacted nitrobenzene.

In the same manner there can be reduced for example nitrobenzene sulfonic acid or benzyl cyanide to phenyl ethyl amine or adipic acid diamide to hexamethylene diamine or acetamide to ethyl amine.

Example 27 A cotton fabric is soaked in a suspension containing per liter 33 g. of Indanthrene orange RRTS (Schultz Farbstoiftabellen, 7th edition, volume II, page 131,

20.5 g. of sodium carbonate and 7.5 g. of diborazyl.

Subsequently the cotton fabric is squeezed uniformly between 2 rolls until the amount of liquid remaining on the fabric comprises about 85% of the net weight of the fabric. Thereafter it is exposed to saturated steam at normal pressure for 2 minutes. Thereupon it is oxidized in a 0.5% solution of sodium perborate and boiled in a 0.5% soap solution, washed and dried. An orange dyeing is obtained.

A similar result is obtained if instead of the diborazyl 35 there are used 11.3 g. per liter of isopropyl borazane.

If to the boron hydrogen solution there are added per liter 1 g. of the sodium salt of anthraquinone-Z-sulfonic acid or 1 g. of K [Co(CN),] a dyeing is obtained which is in the case of the diborazyl 10 fold stronger and in the case of the isopropyl borazane 3 fold stronger.

A similar result is obtained with other vat dyes, for example with Indanthrene brilliant green FFB (Schultz Farbstofftabellen, 7th edition, volume II, page 128).

In a similar manner there can be used intsead of the diborazyl in a stronger alkaline medium the N-methyl borazane.

If a mixture of the above-mentioned catalysts is used 20 a better result is obtained than by usi g only one of these catalysts. a

We claim:

1. In a process for the reduction of a vat dyestuff with 5 an alkali-metal borohydride, the improvement which consists in carrying out the reduction in the presence of a catalytic proportion of a catalyst composition of the group consisting of a (a) aqueous colloidal sols of a metal of the group consisting of tin, arsenic, copper, molybdenum, nickel, cobalt, and platinum, and

(b) alkali-metal salts of complex anions of the group consisting of cyan-onickelate(ll cyanocobaltate(1l), cyanochromate(II), and cyanomanganate(ll), and their oxidized forms.

2. A process as defined in claim 1 in which the catalyst composition is an aqueous colloidal sol of copper.

3. A process as defined in claim 1 in which the catalyst composition is an alkali-metal salt of the divalent tetracyanonickel(ll)ous acid [H Ni(CN) 4. A process as defined in claim 1 in which the catalyst composition is an alkali-metal salt of the trivalent tetracyanon-ickel(ll)ic acid [H Ni(CN) 5. A process as defined in claim 1 in which the catalyst composition is an alkali-metal salt of the tetravalent hexacyanocobalt(ll)ous acid [H Co(CN) 6. A process as defined in claim 1 in which the catalyst composition is an alkali-metal salt of the trivalent hexacyanocoba.lt(IlI)ic acid [H Co(CN) References Cited in the file of this patent UNITED STATES PATENTS 2,304,502 Hopkins et al. Dec. 8, 1942 2,745,788 Frohnsdorff et al May 15, 1956 2,856,428 Brown Oct. 14, 1958 2,898,333 Jullander Aug. 4, 1959 3,000,688 Schubert et al Sept. 19, 1961 OTHER REFERENCES Gaylord, Reduction With Complex Metal Hydrides, Interscience Publishers, Inc., New York, 1956, p. 312.

Jacoby et al., The Application of Vat Dyes, American Association of Textile Chemists and Colorists, 1953, pp. 222-224.

Fox, Vat Dyestuffs and Vat Dyeing, John Wiley & Sons, Inc., New York, 1947, page 37.

Claims

1. IN A PROCESS FOR THE REDUCTION OF A VAT DYESTUFF WITH AN ALKALI-METAL BOROHYDRIDE, THE IMPROVEMENT WHICH CONSISTS IN CARRYING OUT THE REDUCTION IN THE PRESENCE OF A CATALYTIC PROPORTION OF A CATALYST COMPOSITION OF THE GROUP CONSISTING OF (A) AQUEOUS COLLOIDAL SOLS OF A METAL OF THE GROUP CONSISTING OF TIN, ARSENIC, COPPER, MOLYBDENUM, NICKEL, COBALT, AND PLATINUM, AND (B) ALKALI-METAL SALTS OF COMPLEX ANIONS OF THE GROUP CONSISTING OF CYANONICKELATE (II), CYANOCOBALTATE (II), CYANOCHROMATE (II), AND CYANOMANGANATE (II), AND THEIR OXIDIZED FORMS.