DE1228274B - Production of p-halogenated alpha-amino-anthraquinones - Google Patents

Description

Preparation of p-halogenated a-amino-anthraquinones It has been found that p-halogenated a-amino-anthraquinones are obtained in good yield and with high purity if n-amino-anthraquinones of the general formula are obtained in which R is hydrogen, chlorine, bromine, a nitro or an α-amino group and n is the numbers 1 or 2, converted in a manner known per se with N, N-dialkylformamides and acid chlorides into anthraquinonylformamidinium salts, the salts in concentrated sulfuric acid or chlorosulfonic acid, optionally containing SO3, is halogenated with the addition of known halogenation catalysts and the halogenation products are then saponified with dilute acid in a manner known per se.

The anthraquinonyl formamidinium salts are found in US Pat concentrated sulfuric acid, oleum or chlorosulfonic acid resistant even to heat; Surprisingly, the α-formamidinium group directs in these solvents Halogen almost exclusively in the p-position.

The ca-aminoanthraquinones to be halogenated according to the invention at which can be a-mono-, di- or triamino-anthraquinones, must at least contain a free ca position to an amino group in which the Halogen atom enters. Such a-amino-anthraquinones are e.g. 1-amino-anthraquinone, 1-amino-5-chloro-anthraquinone, 1-amino-6-chloro-anthraquinone, 1-amino-7-chloro-anthraquinone, 1-amino-8-chloro-anthraquinone, 1-amino-6,7-dichloro-anthraquinone, 1-amino-5,8-dichloro-anthraquinone, 1-amino-5-nitro-anthraquinone, 1,5-diamino-anthraquinone, 1,8-diamino-anthraquinone, 1,4,5-triamino-anthraquinone.

The conversion of the ca-amino-anthraquinones in formamidinium salts is known, for example from Belgian patent 540870. Anthraquinonylformamidinium salts are obtained in practically quantitative yields from the starting material according to the invention Amino-anthraquinones used by reaction with N, N-dialkyl-formamides, z. B. dimethylformamide, diethylformamide, N-formyl-pyrrolidine, N-formyl-piperidine or N-formyl-morpholine, and acid chlorides, such as phosphorus oxychloride, thionyl chloride, Phosgene or benzenesulfochloride, in a solvent or diluent, for example Nitrobenzene, o-dichlorobenzene or chlorobenzene, at an elevated temperature, is expedient between 50 and 100 ° C.

The halogenation of the anthraquinonylformamidinium salts is simple Way feasible. Can be used as a solvent for the halogenation according to the invention concentrated sulfuric acid with a content of 95 to 1001 / o H.S04, oleum - preferably up to 20% SOS content - as well as chlorosulfonic acid can be used. The concentration the solutions of the formamidinium salts can be varied within wide limits and lies preferably between 5 to 15 times the amount by weight of solvents. Is at Use of oleum, as a solvent, the SOS content a little more than 1 mol - based to 1 mole of the aminoanthraquinone - the chlorination also succeeds in the closed Carry out vessel.

The halogenation catalysts usually used for this purpose can be used Compounds are used, e.g. B. iron chloride, chlorosulfur and especially iodine. They are used, for example, in amounts from 0.1 to 5, advantageously from 1 to 3 percent by weight the product to be chlorinated.

The chlorination takes place at temperatures between 0 and 30 ° C in an exothermic manner Reaction instead. Already at 5 to 10 ° C, when exposed to Cl, becomes smoother Reaction added with elimination of 1 mol of HCl, 1 atom of chlorine per formamidinium residue, practically exclusively p-chlorination takes place. With sufficient fine distribution of the halogen carrier and sufficient chlorine dosage is in the liquid the time required is generally between 0.5 and 2 hours.

It is also sufficient for p-bromination of the anthraquinonylformamidinium salts usually 1 mole Bromine per formamidinium residue. Often one comes but with less than 1 mole, as part of the hydrogen bromide released is oxidized again to bromine by SO3. The bromination is expediently at elevated temperature, advantageously 80 to 120 ° C, made; .The reaction time can up to 12 hours.

After taking up 1 atom of halogen per formamidinium residue, .- that: starting product consumed and the desired reaction product formed. Thin-layer chromatography is an exact tool for determining the endpoint of halogenation a sample saponified in dilute acid.

--- The saponification of the halogenated formamidinium salts is carried out in an made in a known manner with dilute mineral acid at elevated temperature. After the halogenation, it is expedient to dilute with water or in water stirred in until a dilute, preferably 5- to 20% strength sulfuric acid is obtained will; this solution is heated for about 1 to 4 hours: about 80 to 90 ° C., sucks then the resulting p-halogenated a-amino-anthraquinones .ab, washes neutral and dried. The halogenated formamidinium salts can also be isolated, e.g. B. in the form of their sparingly soluble nitrates, and as such in dilute mineral acid, for example in hydrochloric acid, the pH of which is about 0 to 1, saponify.

The yields obtained by the process according to the invention come very close to theory. The quality of the p-halogenated a-amino-anthraquinones is in most cases excellent, so that further cleaning is not necessary.

A particular advantage of the method according to the invention is that that the preparation of the formamidinium salt and its halogenation in the same Can carry out a vessel if the formamidinium salt: -not in the organic medium, but - in an OH group-free - inorganic solvent or diluent, such as B. in excess thionyl chloride. Or phosphorus oxychloride, then forms Ol.eum admits and lets halogen act.

It is surprising, and could not have been foreseen, that the anthraquinonyl-ca-formamidinium group, under the conditions used, would affect the halogen. so clearly üi: p-position directed - because, from the comparable behavior - from. 1-Amino-anthraquinone, the amino group of which - under analogous conditions - directs the chlorine into the non-amidated nucleus like a substituent of the second order; One should have expected that -just the positively charged form. amidinium residue dei. inactivated him carrying benzene nucleus.

The accessible according to the method according to the invention, for. part So far unknown chloramino-anthraquinones are - valuable - intermediate products for the production of dyes.

-: In the following examples, the parts mean unless otherwise stated. Parts by weight. Voliun7-parts relate - to parts by weight as Liters to kilograms.

-_Example 1` _. 63 parts of N '., N'-Dimethyl-N-a-anthraquinonyl-formanidinium chloride, that from 45.5 parts of 98% 1-amino-anthraquinone, 21 parts of dimethylformamide and. 31 parts of thionyl chloride in 200 parts of chlorobenzene by heating for two hours at 50 ° C, below 20 ° C in 300 parts by volume 10% Oleum entered. In this solution, after adding 2 parts, it is finely powdered Iodine passed in chlorine at 5 to 10 ° C until the: -weight increase 14.2 parts amounts to. One stirs - 1st hour after; then carries the ... melt to 8000 parts of water, to which some technical bisulfite solution was added and heated the solution 3 hours to 80 to 90 ° C. The 1-amino-4-chloro-anthraquinone crystallized out in uniform needles is suctioned off at about 60 ° C and washed neutral with warm water. After this Drying gives 49 parts = 95% of theory from a mp of 175 to 177 ° C (pure mp: 179 to 180 ° C). Chlorine content: 14% (theoretical: 13.8%). The product still contains 2 to 3 0/0 1-amino-anthraquinone and 3 to 4 0/0 1-amino-2,4-dichloro-anthraquinone. The net yield. of 1-amino-4-chloro-anthraquinone, based on the 1-amino-anthraquinone used, is 89 to 90% of theory. Example 2 8 parts of N ', N'-dimethyl-N-α-anthraquinonyl-formamidinium chloride are dissolved below 20 ° C in 80 parts by volume of sulfuric acid monohydrate and after Add 0.3 parts of finely powdered iodine at 10 to 20 ° C and with good gas distribution Treated with chlorine until a sample saponified in dilute sulfuric acid that required to absorb one atom of chlorine per anthraquinone molecule Has chlorine retention. Excess chlorine and hydrogen chloride formed are driven off with air and the melt in 750 parts of water, the 15 parts by volume 65%. HN03 were added, introduced. The deposited anthraquinonyl-l-formamidinium nitrate is sucked off and washed with dilute nitric acid of the same concentration. The nitrate is added to 200 parts of water and the pH of the mixture is adjusted Addition of hydrochloric acid to 0 to ... 1 and heated to 80 to 90 ° C. for 2 hours about 5.6 parts = 86% of theory. .chromatographically pure 1-amino-4-chloro-anthraquinone.

Used as a solvent for chlorination instead of sulfuric acid monohydrate Chlorosulfonic acid, a 1-amino-4-chloro-anthraquinone is obtained in a similar yield practically the same quality. EXAMPLE 3 330 parts of thionyl chloride are added Water cooling drop in 39 parts of dimethylformamide and then stir in 30 Minutes at 45 to .50 ° C. Then below 25. °. C (cooling with ice water) 91 parts of 98% 1-amino-anthraquinone registered and the formation of N ', N'-dimethyl-N-aanthraquinonyl-formamidinium chloride by heating for two hours to 50 ° C completed. One cools again with ice water, lets 120 parts by volume of 65% oleum drip in, adds 3 'files of finely powdered iodine and directs. now at 5 to 10 ° C. Chlorine in until the weight gain. 28.4 parts (duration about 80 minutes). The. -Melt is stirred for 1 hour and then to 8000 parts of water to which a little technical bisulfite solution was added. .discharged. For saponification, the mixture is heated to 80 to 90 ° C for about 4 hours, and suctioned off at 50 to 60 ° C and washed neutral with warm water. Yield: 103 parts of 1-amino-4-chloro-anthraquinone = 100% of theory from a temperature of 172 to 174 ° C. Chlorine content: "13.9% (theoretical: 13.8%). Degree of purity (determined by benzoylation): 87%. Example 4 15.7 parts of N ', N'-dimethyl-N-, x-anthraquinonylformamidinium chloride are dissolved in 100 parts by volume of 3% oleum, 0.5 part of finely powdered iodine is added and 8 parts of bromine were added dropwise at 20 to 25 ° C. The mixture is stirred for 2 hours at 60 ° C and 10 hours at 100.degree. C., then let the melt cool down and carry it to 3000 parts Water to which some technical bisulfite solution has been added. For saponification is stirred for 2 to 3 hours at 80 to 90 ° C, suction filtered at 50 to 60 ° C and neutral washed. The 1-amino-4-bromo-anthraquinone obtained melts at 172 to 175 ° C. Yield: 14.2 parts = 94% of theory. Bromine content: 26.2% (theoretical: 26.5%). example 5 17.5 parts of N ', N'-dimethyl-N- [5-chloro-.anthraquinonyl- (1)] - formamidinium chloride, which by stirring 25.8 parts of 1-amino-5-chloro-anthraquinone for two hours with 10 parts of dimethylformamide and 15 parts of thionyl chloride in 200 parts of chlorobenzene at 50 to 60 ° C, suction and washing with chlorobenzene and acetone were dissolved in 100 parts by volume of 10% oleum, 0.5 part of finely powdered Iodine was added and chlorine was passed in at 5 to 10 ° C. until the weight increased of 3.6 parts is obtained. The mixture is stirred for 1 / q hour and the melt is then carried to 3000 parts of water to which some technical bisulfite solution was added .aus. The formamidinium salt is saponified by stirring for 2 to 3 hours at 80 to 90 ° C, the separated product is suctioned off at 50 to 60 ° C and neutralized with warm water washed. Yield: 14.2 parts of 1-amino-4,5-dichloro-anthraquinone = 97% of theory. Chlorine content: 24.7% (theoretical: 24.31 / o). F. after recrystallization, from chlorobenzene: 231 to 233 ° C. Solution color in concentrated sulfuric acid: greenish yellow, on Formaldehyde addition: violet.

In a corresponding manner, 1-amino-8-chloro-anthraquinone can be converted into 1-amino-4,8-dichloro-anthraquinone can be obtained. Broad orange-colored needles recrystallized from 1,2-dichlorobenzene from the mp 248 ° C. Example 6 19.2 parts of N ', N'-dimethyl-N- [5,8-dichloro-anthraquinonyl- (1)] - formamidinium chloride, which by stirring for two hours 29.2 parts of 1-amino-5,8-dichloro-anthraquinone with 10 parts of dimethylformamide and 15 parts of thionyl chloride in 200 parts of nitrobenzene at 50 to 60 ° C, suction and washing with nitrobenzene and acetone were, are chlorinated according to the information in Example 5. Receives after saponification 15.5 parts of 1-amino-4,5,8-trichloro-anthraquinone = 95% of theory. Chlorine content: 32.9% (theoretical: 32.6%). F. after recrystallization: 300 to 302 ° C.

Example ? 18 parts of N ', N'-dimethyl-N- [5-nitro-anthraquinonyl- (1)] -formamidinium chloride (made from 1-amino-5-nitro-anthraquinone, dimethylformamide and thionyl chloride in nitrobenzene at 50 to 60 ° C) are chlorinated according to the information in Example 5. After saponification, 15 parts of crystallized 1-amino-4-chloro-5-nitro-anthraquinone are obtained = 99% of theory. Chlorine content: 12 0/0 (theoretical: 11.7 0/0). F. after recrystallization from nitrobenzene: 287 to 289 ° C. Orange-colored needles that are concentrated in Dissolve sulfuric acid pale yellow; if formaldehyde is added, the solution color suggests to reddish blue.

Example 8 21 parts of anthraquinonylene-1,5-diformamidinium chloride were obtained from 1,5-diamino-anthraquinone, dimethylformamide and thionyl chloride, are in 100 Dissolved parts by volume of 10% oleum and added part of finely powdered iodine. At 100 to 110 ° C., 16 parts of bromine are added dropwise over 2 hours and the mixture is stirred another 8 hours at this temperature. Then, as in Example 5, it is saponified and worked up. 19.5 parts of 1,5-diamino-4,8-dibromo-anthraquinone = 98.5 are obtained % of theory. Bromine content: 41.4% (theoretical: 40.4%). The product is by little 1,5-diamino-2,4,8-tribromo-anthraquinone contaminated.

Example 9 21 parts of anthraquinonylene-1,8-diformamidinium chloride (prepared from 1,8-diamino-anthraquinone, dimethylformamide and thionyl chloride at 100 ° C) dissolved in 9.00 parts by volume of 10% oleum and after adding 0.5 parts of finely powdered Treated iodine at 5 to 10 ° C with 7.1 parts of chlorine. With saponification and work-up according to example s one obtains a 1,8-diamino-4,5-dichloro-anthraquinone, which by little ß-chlorinated product is contaminated. Yield: 14.3 parts = 93% of theory. Chlorine content: 24% (theoretical: 23.1%).

Claims (1)

Claim: Process for the preparation of p-halogenated, x-amino-anthraquinones, characterized in that one cx-amino-anthraquinones of the general formula in which R is hydrogen, chlorine, bromine, a nitro or an α-amino group and n is the numbers 1 or 2, converted in a manner known per se with N, N-dialkylformamides and acid chlorides into anthraquinonylformamidinium salts, the salts in concentrated sulfuric acid or chlorosulfonic acid optionally containing SO. halogenated with the addition of known halogenation catalysts, and the halogenation products are then saponified with dilute acid in a manner known per se. Considered publications: German Auslegeschriften Nr. 1132 931, 1154489.