Patented Oct. 28, 1952 2,615,898 UNITED STATE s PATENT OFFICE BENZOTHIOPHENE ANTHRAQUINONE DYESTUFFS - Fritz Max, Staten Island, N. Y., and Wilhelm Schmidt-Nickels, Little York, N. J., assignors to General Aniline & Film Corporation, New

York, N. Y., a corporation of Delaware No Drawing. Application October 14, 1948, Serial No. 54,582 . . . . . 12 Claims. (CI. 260-329.2) This invention relates to novel dyestuffs of the wherein the first compound has four unsubstis benzothiophene anthraquinone Series. tuted alpha-positions in the anthraquinone nu More specifically, the invention relates to novel cleus and the second compound has three unsub a-amino-benzothiophene anthraquinones which stituted alpha-positions...... are valuable as dyestuffs for organic derivatives In preparing the novel dyestuffs suitable for of cellulose, particularly cellulose esters and coloring cellulose esters and ethers in accordance ethers such as cellulose acetate and ethyl cellu with this invention, the aforesaid benzothiophene lose and fibers or textile materials containing the anthraquinones are subjected to nitration by treat same, such dyestuffs being applied to the afore ment With a mixture of concentrated nitric and said materials in the form of an aqueous disper O Sulfuric acids. An d-dinitro benzothiophene an sion. Further, the invention relates to d-aroyl thraquinone is thereby formed wherein the a amino benzothiophene anthraquinones, corre nitro groups apparently occupy the 15- and 1.8- sponding to the aforesaid d-amino derivatives positions of the anthraquinone nucleus. The a and prepared therefrom by reaction with an aryl dinitro compounds are thereupon Subjected to re. carboxylating agent, which are valuable vat dye 5 duction, for example, by heating with an aqueous stuffs suitable for producing colorations on cellu alkali metal sulfide solution, yielding the corre losic fiber and textiles by conventional vat dyeing sponding diamino - benzothiophene anthraquin or printing procedures. OneS. . ". . . . The novel dyestuffs of this invention are pre Additional amino groups can be introduced in pared from benzothiophene anthraquinones, ad 20 to the remaining unsubstituted alpha-positions vantageously obtained by the process of our co of the anthraquinone nucleus by acylating the pending application, Serial No. 53,148 filed Octo aforesaid adianino compounds, with oxalic acid, ber 6, 1948, now U. S. Patent 2,533,171, dated De to form the corresponding dioxaminic acid, Sub cember 5, 1950, by condensation of phthalic an jecting this compound to nitration with concen hydride with a dibenzothiophene (diphenylene 25 trated sulfuric acid and nitric acid, reducing the sulfide) and ring closure of the resulting ortho additional nitro groups thereby introduced to 2-dibenzothenoyl benzoic acid in the presence of . amino groups by reaction with alkali metal sulfide a mixture of ortho-phosphoric acid and phos and reconverting the oxaminic acid groups to phorus pentoxide. Since the initial condensation amino groups by alkaline hydrolysis...... of dibenzothiophene with phthalic anhydride re 30 The d - polyamino-benzothiophene anthraqui sults in substitution of one of the benzene rings nones of this invention, produced as indicated of the dibenzothiophene nucleus in para-position 3. above, are water-soluble compounds which can be to the sulfur (i. e., the 2-position), the sulfur oc dispersed in aqueous media with a suitable dis cupies a beta-position of the anthraquinone nu persing agent to yield dye baths from which or cleus in the resulting benzothiophene anthra 35 ganic derivatives, particularly ethers and esters, quinone, and the anthraquinone nucleus retains of cellulose, e. g., cellulose acetate, cellulose bu at least three unsubstituted alpha-positions. . . tyrate, ethyl cellulose, cellulose acetate, butyrate, Thus, the benzothiophene anthraquinones are in the form of a fiber or textile material contain believed to be a mixture of two compounds have ing the same, can be dyed-in brilliant Orange to ing the following nuclear structures: 40 Scarlet to blue Shades of outstanding fastness properties...... s. ; : CO The vat dyestuffs of this invention are the poly - d -aroylamino-benzothiophene anthraqui nones corresponding to the aforesaid poly-a- C Yo6O ^Ns 45 amino Compounds. They are conveniently pro duced by reacting the poly-a-amino benzothio. and phene anthraquinones of the invention. With an aryl carboxy acid halide such as benzoyl chloride, 2-methoxy - 3 - naphthoyl chloride, 1-amino 50 anthra.cuinone-2-carboxy acid chloride, or the corresponding bromides or anhydrides, in an or ganic Solvent such as nitrobenzene in the pres ence of a basic compound Such as an alkali metal carbonate. The resulting poly - a - aroylamino 55 benzothiophene anthraquinones can be applied to cellulosic fiber such as cotton or regenerated cel lulose or textile materials containing the same, 3,615,898 3 4. V. V. from an alkaline hydrosulfite vat or printed rivatives of cellulose when applied thereto from thereon in the form of a wait printing composi aqueous dispersions. tion. Upon subsequent aging to effect reoxida tion on the fiber, strong yellow shades of excel Eacample 2 lent fastness properties are produced. 5 The a-diamino-benzothiophene anthraquinone The invention is illustrated by the following of Example 1 is converted to the corresponding examples Wherein the parts and percentages are a-dioxaminic acid by heating it with four times by weight and the temperatures are in degrees its Weight of oxalic acid at a temperature of centigrade. 100-150 until the unreacted diamino compound Eacample 1 is no longer present. Excess oxalic acid is re Owed from the reaction mixture by extraction 47.1 parts of benzothiophene anthraquinone with: Water, and the residue is dried and subjected prepared by condensing phthalic anhydride with to nitration with a mixture of concentrated sul dibenzothiophene in the presence of aluminum furic acid. and nitric acid by the same procedure chloride, and heating the resulting ortho-2-di as that described in Example 1. The nitrated benzothenoyl benzoic acid with an equimolecular product is recovered by drowning the mixture in mixture of Ortho-phosphoric acid and phosphorus ice water. The oxaminic acid groups are recon pentoxide at 170° for 10 minutes, were introduced verted to amino groups by heating with dilute at a temperature below 40° into an agitated mix aqueous caustic Soda. Solution, and the nitro ture of 150 parts of concentrated sulfuric acid groups of the resulting nitrated a -diamino-benzo and 17 parts of a mixture of nitric acid and thiophene anthraquinone are reduced to amino concentrated sulfuric acidina, ratio of 1:2. When groupS by heating with aqueous sodium sulfide, as the addition is complete, the mixture is agitated described in Example 1. The resulting insoluble at 40° for 1 hour, then cooled to 20° and poured a-polyamino-benzothiophene anthraquinone is into ice water. Alpha-dinitro-benzothiophene 25 recovered from the reaction mixture, by filtration, anthraquinone is thereby precipitated, and re Washed with water and dried. The resulting.com covered in the form of a filter cake by filtration. pound contains amino groups in each of the a The filter cake is Washed with Water and intro positions of the anthraguinone nucleus available duced into a solution, heated to 95, Inade by for substitution in the original benzothiophene adding 180 parts of crystalline Sodium sulfide 30 anthraquinone. , (Na2S,9H2O) and 110 parts of 20% aqueous so The resulting a-polyamino-benzothiophene-an dium hydroxide. solution to 875 parts of water. thraquinone can be dispersed in an aqueous dye The resulting mixture is stirred at 95-100 for bath as disclosed in the preceding example and one-half hour to effect complete reduction of the applied in dyeing cellulose acetate fiber, whereby nitro groups to amino groups. The resulting a reddish-blue colorations of good fastness. proper diamino-benzothiophene anthraquinone is re ties can be obtained. covered by filtration in the form of a filter cake, By employing substituted a -diamino-benzothio washed with water until neutral and dried. phene anthraquinones of the preceding example, To prepare a dye bath from the resulting a correspondingly substituted a-polyamino-benzo -diamino compound, 0.6 part thereof can be dis 0. thiophene anthraquinones are obtained in the solved in a Small quantity of a mixture of equal process of this example. parts of alcohol and acetone, followed by admix ture of 40 parts of a 50% aqueous solution of N,N- Eacample 3 Öley methyl tatrine sodium salt or of a similar 9.8 parts of the a-diamino-benzothiophene: an Saponaceous dispersing agent, and diluting the 45 thraquinone of Example 1 are mixed with 120 mixture with 5000 parts of warn Water at 45-55°. parts of nitrobenzene containing 12.2 parts of 100 parts of Cellulose acetate Siki, the form of benzoyl chloride, and 9.1 parts of sodium car yarn or fabric, is then worked into the dye bath bonate are added thereto. The mixture is heated while raising the temperature to 80-90. When while agitating at a temperature of 200-2059 for the dyeing is complete, the dyed material is re 50 5 hours. The reaction mixture is then allowed moved from the dye bath, soaped, rinsed and to cool and the benzoylated product. which sep dried. A billiant Scarlet Shade of good fastness arates from the mixture is recovered by filtration, properties. is produced on the fiber or textile:Ina washed with nitrobenzene and dried. For puri - 'teria. " - fication the resulting product is dissolved in con Instead of unsubstituted benzothiophene an 55 centrated sulfuric-acid, drowned in dilutelaqueous thraquinone employed in the foregoirag eSan alkali metal bichromate, the resulting slurry ple, substituted benzothiophene anthraquinones boiled for a short time and the insoluble product can be used as starting materials containing, for recovered by filtration. The product is then example, chlorine, bromine or a nitro group in boiled with a dilute alkaline sodium hypochlorite the benzene ring of the benzothiophene nucleus 60 Solution, separated by filtration, washed and in para-position to the Sulfur, obtained by ring dried. Alpha - dibenzoylamino-benzothiophene closure of 8-chloro-, 3-bromo or 8-nitro-ortho-2- anthraquinone is thereby obtained in sufficient dibenzothenoyl benzoic acid. The mono-halo purity and in Satisfactory form for use as a wat benzothiophene anthraquinones, yield the corre dyestuff. sponding halo-a-polyamino-benzothiophene: an 65 The compound dissolves in an alkaline hydro thraquinones upon nitration and reduction as dis sulfite vat to yield a dye bath which dyes cotton closed in the foregoing example, while the prod in strong Orange yellow shades of excellent fast ict obtaired from the aiforesaid ironbenzo neSS properties, after Subsequent aging to oxidize thiophene anthraeuinone: yields an a-diamino the dyestuff on the fiber. W benzothiophene anthraquinone having a third 70 Similar benzoylation of the a-polyamino-ben amino group in the benzene ring of the benzo Zothiophene anthraquinone of Example 2 and of thiophene. nucleus, resulting fron reduction of the corresponding substituted diamino- and poly the nitro group originally present therein. The anino-benzothiophene anthraquinones contain resulting polyamino Compounds likewise, yield ing chlorine, bromine or an additional amino brilliant scarlet to orange shades on organic de 75 group in the benzene ring of the benzothiophene

2,615,898 5 6 nucleus, described in Examples 1 and 2, likewise thiophene nucleus occupies a beta-position of the yields vat dyestuffs suitable for producing shades anthraquinone nucleus. of similar brilliance and fastness properties On 5. As a new product, suitable for producing cellulosic materials by the aforesaid vat dyeing colorations on cellulosic materials by vat dyeing procedure. Sinnilarly, the vat dyestuffs of the procedures, an a-diaroylamino benzothiophene invention can be incorporated in vat printing anthraquinone, wherein the Sulfur of the benzo compositions and applied in this form to produce thiophene nucleus occupies a beta-position of the colorations of equal quality on cellulosic mate anthraquinone nucleus. rials. 6. As a new product, a -dibenzoylanino benzo Instead of benzoyl chloride, other aromatic O thiophene anthraquinone. carboxylic acid chiorides, bromides or anhydrides 7. The process for preparing dyestuffs suitable can be employed in the aroylation reaction of the for coloration of organic derivatives of cellulose, preceding example. Thus, 2-methoxy-3-naph which comprises nitrating a benzothiophene thoyl chloride, anthraquinone-2-carboxylic acid anthraquinone, wherein the Sulfur occupies a chloride, 1 - anino - anthraquinone-2-carboxylic 5 beta-position of the anthraquinone nucleus and acid chloride, or the corresponding bromides or at least three alpha-positions of the anthraqui anhydrides can be used to form Wat dyes from the none nucleus are unoccupied, and reducing the amino compounds of Examples 1 and 2 in the nitro groups in the resulting compound to amino manner disclosed in Example 3. grOOS. While the structure of the dyestuffs produced 20 8. The process for preparing dyestuffs suitable in accordance with this invention have not been for coloration of organic derivatives of cellulose, demonstrated, they are apparently mixtures of which comprises nitrating a benzothiophene compounds having the benzothiophene anthra anthraquinone, wherein the sulfur Occupies a quinone structures set out above, Wherein the beta-position of the anthraquinone nucleus and Sulfur of the benzothiophene nucleus Occupies a 25 at least three alpha-positions of the anthraqui beta-position of the anthraquinone nucleus. none nucelus are unoccupied, reducing the nitro Nitro groups introduced by nitration and the COr groups to amino groups, converting the amino responding amino groups introduced as disclosed groups to oxaminic acid groups, nitrating the in Example 1, and the corresponding aroyalamino resulting polyoxaminic acid compound, reducing groups formed as disclosed in Example 3 appar 30 the nitro groups formed by nitration to amino ently occupy the 15- and 1,8-positions of the groups, and saponifying the Oxaminic acid groups anthraquinone nucleus in the aforesaid nuclear to amino groupS. structures; while the additional nitro, amino and 9. The process for preparing a dyestuff suitable aroylamino groups introduced as disclosed in for coloration of organic derivatives of cellulose Examples 2 and 3 occupy the remaining a-posi 35 which comprises dinitrating benzothiophene ann tions of the anthraquinone nucleus in the afore thraquinone, wherein the sulfur occupies a beta said structures. Substituents initially present in position of the anthraquinone nucleus, and reduc the Ortho-2-dibenzothenoyl benzoic acid from ing the resulting a-dinitrobenzothiophene an which the dibenzothiophene anthraquinones are thraquinone to the corresponding a -diamino formed occupy a position para, to the sulfur atom 40 compound. in the benzene ring of the benzothiophene 10. The process for preparing a vat dyestuff nucleus. which comprises acylating the free amino groups Wariations and modifications which are obvious of a dyestuff prepared according to claim 7, With to those skilled in the art can be made in the an aryl carboxylating agent. foregoing processes and products without depart 1i. The process for preparing a vat dyestuff ing from the scope of the invention. which comprises aroylating the final polyamino We cairn: dyestuff of claim 8, with an aryl carboxylating 1. As a new product, Suitable for producing agent. colorations on Organic derivatives of cellulose, an 12. The process for preparing a vat dyestuff a - polyamino - benzothiophene anthraquinone 50 Which comprises reacting the dyestuff prepared compound, wherein the sulfur of the benzothio according to claim 9 With a benzoylating agent. phene nucleus occupies a beta-position of the FRITZ, MAX. anthraquinone nucleus. WILHELM SCHMONICKELS. 2. As a new product, Suitable for producing colorations on organic derivatives of cellulose, an 55 REFERENCES CTED a-diamino-benzothiophene anthraquinone COm The following references are of record in the pound, wherein the sulfur of the benzothiophene file of this patent: nucleus occupies a beta-position of the anthra quinone nucleus. UNITED STATES PATENTS 3. As a new product, suitable for producing 60 Number Name Date colorations on Organic derivatives of cellulose, 2,281.583 Kranzlein ------May 5, 1942 a-diamino-benzothiophene anthraquinone. 4. As a new product, Suitable for producing OTHER REFERENCES colorations on cellulosic materials by vat dyeing Georgievics: Textbook of Dye Chemistry, pp. 56 procedures, an a-polyaroylamino benzothiophene and 57, Scott, Greenwood and Son, London, 1920. anthraquinone, wherein the Sulfur of the benzo J. Org. Chen. 3, 119 (1938).