DE555081C - Process for the preparation of 1íñ2-benzanthraquinones - Google Patents

Description

Process for the preparation of 1-2 eenzanthraquinones In the patent 298,345 is a process for the preparation of oxyanthraquinones and their derivatives described, which consists in the fact that one phenols, naphthols, oxyanthracenes or their derivatives with phthalic anhydride or its derivatives in the presence of Aluminum chloride is heated to temperatures exceeding 150 ° until formation the anthraquinone derivatives are completely or almost complete.

Your investigations have now shown that the products obtained in this way from β-naphthol and its derivatives are not oxyanthraquinones, but probably derivatives of i # 8-phthaloylnaphtlialin are. The body known as Oxynaphtbanthraquinone, which can be obtained from phthalic anhydride, ß-naphthol and AIC13 according to example 4 of said patent specification, has z. B. probably the constitution The usual methods can be used to replace the oxy group in it with other substituents such as halogen, the amino group, etc., or with hydrogen, which leads to new compounds which, because of their insolubility in alkaline hydrosulfite solutions, cannot be naphthanthraquinones.

It has now been found that this is referred to below for short as i # 8-phthaloylnaphthalene Designated product and its derivatives with at least one free o-position to one of the carbonyl groups in the naphthalene residue by heating with strong acids rearranged into the i # 2-benzanthraquinone or substituted r # 2-benzanthraquinones will. In cases where the primary expected Products under The reaction conditions are changed further, one also obtains in general conversion products corresponding to the i # 8-phthaloylnaphthalenes. So goes z. B. the i # 8-Phthaloylnaphthalin on heating with sulfuric acid of 78% 150 ° into the i # 2-benzanthraquinone. On the other hand, it arises from the action concentrated sulfuric acid at the same temperature a product that one under the same conditions are also obtained from i # 2-benzanthraquinone. example 1 i Part 2-chloro-i # 8-phthaloy lnaphthalene (can be prepared by reacting the after Example .4 of Patent 298,345 to obtain 2-oxy-i # 8-phthaloylnaphthalene with phosphorus pentachloride in phosphorus oxychloride% d) becomes sulfuric acid in 10 parts (96%) dissolved heated to 10 to 1:25 'for about 15 minutes. When pouring the solution in water the rearrangement product precipitates in a practically pure state. After analysis and method of production, the formula of Bz-2-chloro-i # 2 - b, to enzanthraquinones. It crystallizes from chlorobenzene in yellow needles, which are in sulfuric acid with brown, in alkaline hydrosulphite solution with red Dissolve paint. Example e i part 2-Amino-i # 8-phthaloylnaphthalene (represented by Saponification of that obtained from the chlorine compound by heating with p-toluenesulfamide p-Toluene: sulfamino compound by means of sulfuric acid) is mixed with 10 parts of sulfuric acid (96%) heated to 12o to 125 ° until a sample can be completely vetted. The color the solution changes from yellow to red-brown. By pouring the reaction mixture in water you first get a yellow sulfate, which after suction through Washing out with water as a result of hydrolytic cleavage into the free amino compound transforms. The new compound, presumably the Bz-2-Amino-i # 2-benzanthraquinone, crystallizes from chlorobenzene in violet needles, dissolves in sulfuric acid red-brown color and gives a red-brown Hydros: ulfitküpe.

Example 3 i Part i # 8-Phthaloylnaphthalene- (obtainable by diazotization of the 2-amino-i # 8-phthaloylnaphthalene used as starting material in Example and reduction of the diazonium compound obtained) is 100 parts sulfuric acid from 78 0/0 1 hour heated to 15o to 155o. From that by precipitation with water obtained crude product is obtained by treatment with alkaline hydrosulfite solution and If necessary, the filtered red vat is blown out with air of pure i # 2-benzanthraquinone obtain.

If you use 96% sulfuric acid instead of 78% sulfuric acid, the i # 2-benzanthraquinone that was primarily formed is further modified in this way. The end the product obtainable by salting out the reaction mixture diluted with water after drying is a red-brown powder, which in water with orange, dissolves in sodium hydroxide solution with a bluish-tinged red color and in sulfuric acid with a red-brown color. The same is obtained from i # 2-Benzanthrachiriön under the same conditions Reaction product.

Example 4 Sulfuric acid boiling in 100 parts is about 75% 5 parts of 2-oxy-i # 8-phthaloylnaphthalene entered quickly with thorough stirring. That The reaction mixture is kept boiling for a short time and then rapidly cooled and put in water. The precipitated product is suctioned off and washed Remove the sulphonic acid formed by the way with water until nothing more goes into solution. The reaction product is a red-brown powder, which dissolves in sulfuric acid with a green color and with aqueous solutions of alkali hydroxides and carbonates forms poorly soluble blue alkali salts. The alkaline hydrosulfite vat is red-brown.

The compound is identical to that obtained by diazotizing Bz-2-amino-i # 2-benzanthraquinone and heating the diazo compound in aqueous solution Oxy compound and is therefore probably Bz-a-Oxv-i # '-benzanthraquinone.

Claims (1)

PATENT CLAIM: Process for the preparation of i # 2-Benzanthraquinones, characterized in that the by condensation of, B-naphthol or his Derivatives with phthalic anhydride or its derivatives available products or those made from them by replacing the oxy group with other substituents or with hydrogen Discharge products heated with strong acids.