DE1643239A1 - Process for the preparation of 1-amino-4-nitro- and 1-nitro-4-aminoanthraquinone carboxylic acid (2) - Google Patents

Description

Process for the preparation of 1-amino-4-nitro- and 1-nit @ o-IE-amino-anthraquinonecarboxylic acid- (2 ') -. The invention relates to a process for the preparation of 1-amino-4-nitro and 1-Nitro-4-amino-anthraquinonecarboxylic acid- (2) from 1,4-dinitro-anthraquinonecarboxylic acid- (2).

1-Amino-4-nitroanthraehinonecarboxylic acid- (2) is known to be an important one Intermediate product for the synthesis of dyes. It is obtained by nitration of 1-amino-anthraquinonecarboxylic acid- (2) produced in the presence of formaldehyde (Fiat report 1313, Vol.II, page 70). 1-Amino-anthraquinonecarboxylic acid- (2) itself is converted from 1-nitro-.2-methylanthraquinone in two stages by oxidation of the methyl group and exchange of the nitro group for the amino group received, In the technical execution of the multi-stage process, the Intermediate products are each dried and ground, what with a considerable Time, energy and equipment expenditure is connected.

Attempts to obtain 1-amino-4-nitroanthrachirloncarboxylic acid (2) from 1,4-dinitroanthra, quinoneaxboxylic acid (2), which starting from 1-nitro-2-ethylanthraquinone on the way via the C-methyl-anthraquinone (N), 2-isoxazole by treatment with nitric acid easily and in good Yields can be produced (German Patent 961 806) by reduction in acidic medium, e.g. B. by Xüpfer powder in 'sulfuric acid to produce, led only for the formation of the 1,4-diamino compound (cf. German Patent 1,031,293). It has now been found that 1-amino-4-nitro-anthraquinonecarboxylic acid (2) and 1-Nitro-4-amino-anthraquinonecarboxylic acid (2) can advantageously be produced if one 194-dinitroanthraquinone-carboxylic acid- (2), preferably at elevated temperature, optionally in the presence of solvents, treated with ammonia andthis so obtained mixture of 1-amino-4-nitro-anthraquinone-carboxylic acid (2) and 1-nitro-4-amino-anthraquinone-carboxylic acid (2) separates into the components. -According to the new procedure, surprisingly only one will be Nitro group -der 1,1f-Dinitroanthradhinoncarbonsäure- (2) against an amino group exchanged. The formation of the 1,4-diamino compound was not observed.

The mixture obtained by the process contains predominantly the 1-amino-4-nitro-anthraquinonecarboxylic acid (2) in addition to the easily separable and thus also on an industrial scale 1-nitro-4-ami, no-anthraquinonecarboxylic acid (2). On the way from 1-nitro-2-ethylanthraquinone via C-methyl-anthraquinone-1 (N), 2-isoxazole and 1,4-dinitro-anthraquinone carboxylic acid (2) to the end products, the intermediates of the individual stages - mostly processed as water-moist press cakes or pastes, so that the time-consuming drying and grinding of the intermediates is largely unnecessary Carry out liquid ammonia: With this method of operation, after the reaction has ended and the excess ammonia has evaporated, the mixture of the end products is immediately available in dry form. The reaction can, however, also be carried out in inert solvents with sufficient solubility for ammonia and the starting material, for which, for example, organic solvents such as alcohols, ethers, nitriles, amides, tertiary amines or water are suitable. Of the organic solvents, it is advantageous to use isolche which are wholly or partially miscible with water. Examples include methanol, ethanol, isopropanol, isobutanol, methyl glycol, ethyl glycol, tetrahydrofuran, dioxane; Acetonitrile, formamide, dimethylformaemide, N-methylpyrrolidone, pyridine. Surprisingly, the 1,4-dinitroanthraquinone carboxylic acid (2) reacts according to the process of the invention even at room temperature. At this temperature, however, the complete conversion requires 15 to 20 hours. Man leads. therefore the reaction is advantageous at elevated temperature, e.g. B. at 50 to 150 ° C, especially at 80 to 110 ° C. This shortens the reaction times to about 1 to 5 hours. - Depending on whether you are working with or without a solvent, and depending on the reaction temperature and the solvent used, pressures of normal pressure up to about 10 atm are established in the process of the invention.

Normal ones are generally used for the reaction, depending on the pressure Mixing vessels, pressure equipment or autoclaves.

The mixture of the two isomeric end products is expediently under Use of solvents, especially more polar solvents, separated into the components by extraction or fractional crystallization. For example, organic solvents such as alcohols, ketones, ethers, nitriles, Esters, amides, optionally nitrated or halogenated aromatic hydrocarbons, halogenated alkanes, organic acids can be used. There are z. B. called Isobutanol, methyl ethyl ketone, dioxane, acetonitrile, bimethylformamide, N-methyl pyrrolidone, o-dichlorobenzene, nitrobenzene, tetrachlorathane, glacial acetic acid. Particularly beneficial however, concentrated sulfuric acid is used for the separation.

The separation is carried out, for example, by the mixture of isomers Dissolves in 96% strength by weight sulfuric acid, the sulfuric acid concentration by adding water Reduced to 75% by weight and the precipitated sulfate of 1-amino-4-nitroanthraquinonecarboxylic acid re (2) filtered off. The 1-nitro - # - aminoanthr: achinoncarbonsäure- (2) is obtained from the filtrate by adding more water. The 1-nitro = 4-aminoanthraquinone carboxylic acid (2) is new. It is a valuable intermediate dye product, especially for vat dyes, represent.

The parts given in the examples are parts by weight. The weight parts relate to parts by volume as g to ccm. EXAMPLE 1 200 parts of 1,4-dinitroanthraquinonearboxylic acid (2) are introduced into a solution of 250 parts of ammonia in -z2,000-telene methanol and the mixture is stirred at room temperature for 20 hours. It is then filtered off and the mixture of the 1-amino-4-nitro and 1-nitro-4-amino-anthraehinoncarbdnsäuren- (2) @ washed neutral with Waseer. After drying, 170 parts are obtained. of the acid mixture, which is separated in the following way :.

1'j0 parts of the acid mixture are introduced into 1,275 parts of 96% strength by weight sulfuric acid and the mixture obtained is stirred at 58 to 60 ° C. for 1 hour. Thereafter, 187 parts of water are added dropwise in 1 to 2 hours and the mixture is heated to 80 ° to 850 ° C. for 1 hour. After cooling and allowing to stand for 10 hours, it is filtered off, washed with 680 parts of 75% strength by weight sulfuric acid and the filter material is stirred with about 5,000 parts of water. The aqueous suspension is heated to 85 ° C. for 30 minutes, then filtered off with suction, washed neutral and dried. 132 parts of 1-amino-4-nitroanthraehinonecarboxylic acid (2) are obtained in this way.

The mother liquor and the wash filtrate from the sulfuric acid fractionation are combined and poured into approximately 2,600 parts of ice water. After filtration, washing until neutral and drying, 37 parts of 1-nitro-4-aminoanthraquinonecarboxylic acid (2) are obtained, the identity of which is confirmed by elemental analysis: found:. C 57.7% H 2.57% 0.3o.8% N -8.7% '-calculated: C 5771% H 2P7 0 30.8% N 8 $ -97%.

Example 2 -1 500 parts of water, 580 parts of 26% strength by weight ammonia and 1750 parts of an aqueous paste containing 350 parts of 1,4-dinitroanthraquinone carboxylic acid (2) are heated to g0oC for 2 hours. It is allowed to cool, and 350 parts of 35% strength by weight are used Sodium bisulfite solution to destroy the ammonium nitrite formed and 1 200 parts Water is added and a pH value is established by adding 75% strength by weight sulfuric acid of 2 a. Filtration: neutral washing and drying gives 307 parts of acid mixture, which, as described in Example 1, is separated and 218 parts of 1-amino-4-nitroanthraquinone carboxylic acid (2) and gives 74 parts of 1-nitro-4-a.minoanthraquinone carboxylic acid- (2).

Example 3 In a shaking autoclave of 250 parts by volume 25 parts of 1,4-dinitroanthraquinone carboxylic acid (2) and 80 parts of liquid ammonia. and the closed autoclave is shaken for 15 hours at room temperature. After the excess ammonia has been vented off, 19.5 parts of acid mixture are obtained as: described in Example 1, in 11.5 parts of 1-amino-4-nitroanthraquinonecarboxylic acid (2) and 7.5 parts of 1-nitro-4-aminoanthrach_inonca: rboxylic acid- (2) is separated. .3. . -. - Example- -In 40-0 parts of dimethylformamide and 16 parts of ammonia 40 parts of 1,4-dinitroanthraquinonearboxylic acid (2) are suspended and the suspension. is stirred for 20 hours at room temperature. The reaction mixture is poured into 3 000 parts of water, 40 parts of 35gew.jige sodium sulfite solution are added and sets a pH of 2 with 75% strength by weight sulfuric acid. After filtration, wash neutral and drying gives 35.2 parts of an acid mixture, which after separation gives 23.2 parts 1-Amino-4-nitroanthraquinone carboxylic acid (2 :) gives. - -

Claims (2)

Patent claims 1. Process for the preparation of 1 - Amno = 4-nitroänthraquinone-carbonic acid- (2) and 1-nitro-4 = .äminöanthräehinöncarbonaäure- (2), characterized in that 1,4-Dinitroänthrachnöncarbonsäure- (2), preferably at elevated temperature, optionally in the presence of solvents, treated with ammonia and the resulting mixture of 1-amino-4-nitroänthrachnondarboxylic acid (2) and 1-nitro-4-aminoanthraquinonecarboxylic acid (P) is separated into the components. 2. The method according to claim 1, characterized. marked.me, t, that is, the mixture of 1-amino-4-nitro, nthraquinone carbonic acid (2) and 1-nitro = 4 = aminos.nthraquinone carbonic acid - '(2) with the use of concentrated sulfuric acid in the components 3., .1 = nitr; o = @ -: - aminöan hrachnones.rbonäure = (2)