CS225531B1 - Manufacture of 1,4-diamineanthraquinone derivatives with the solubilisation group in its molecule - Google Patents

Description

The invention relates to a process for the preparation of 1,4-diamino anthraquinones with a solubilizing moiety in the molecule from the corresponding 1-amino-4-nitroanthraquinones by reduction.

1,4-Diaminoanthraquinones with a solubilizing group at the 2-position are important semi-products in the chemistry of anthraquinone dyes and have been so far difficult to obtain in pure form. For example, 1,4-diamino anthraquinone-2-sulfoacid is produced by quinizarin amination and the obtained 1,4-diamino anthraquinone is treated with fuming sulfuric acid at temperatures around 190 ° C. Another alternative preparation consists in condensing 1-amino-4-bromoanthraquinone-2-sulfonic acid with arylsulfamide and hydrolyzing the product to the 1,4-diaminoderivative. Both of these syntheses are technically demanding, economically disadvantageous and provide highly polluted and difficult to refine products. The reduction of the available 1-amino-4-nitroanthraquinone-2-sulfonic acid and 1-amino-4-nitroanthraquinone-2-carboxylic acid has not been applied yet, because the reduction with conventional reagents has led to the elimination of substituents and the obtained low percent products were not suitable for technical syntheses.

According to the present invention, the 1,4-diamino anthraquinone derivatives having a solubiating group in the molecule of formula I are used

(I) wherein X is SO4 Me or COOHe and Me is hydrogen or a cation, they produce from aminonitroanthraquinones of formula II

NH,

O (II)

- 2,225,531 wherein X is as defined above, wherein a mixture of water, a selected compound of formula (II), an alkali carbonate, hydroxide, phosphate, ammonia, ammonia, or a mixture of these alkalis and / or buffers controlling pH between 7.5 and 12 and ferrous salts, optionally in the presence of reducing aids, are heated to between 20 ° C and the boiling point of the reaction mixture. 1-Amino-4-nitroanthraquinone-2-sulfonic acid and its salts or 1-amino-4-nitroanthraquinone-2-carboxylic acid and its salts can be obtained for example from 1-aminoanthraquinone-2-sulfonic acid or 1-aminoanthraquinone- 2-carboxylic acids by nitration ·

Of the iron salts, both inorganic salts (chloride, sulfate) and organic salts (acetate, oxalate, citrate) are suitable. Economically advantageous is the use of green vitriol, which falls from the production of titanium dioxide or from pickling of metallurgical materials or of other origin «

Among the alkaline agents are suitable: sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydroxide, potassium hydroxide, ammonia, ammonia or mixtures thereof, phosphates (sodium, potassium, ammonium) or buffering systems controlling pH in the range of 7.5 to 12.

Among the reducing aids, for example, surfactants (wetting agents, antifoams), solvents, quaternary salts and the like can be used. In the reduction in an alkali carbonate environment, for example, the addition of antifoams can significantly reduce foaming and thus shorten the reaction time. The addition of wetting agents accelerates the reductions performed in the suspensions.

In the reductions of the present invention, the reaction conditions can be varied within a wide range. Already at temperatures around 20 ° C, the conversion of the nitro group to amino occurs and the rate of this conversion increases rapidly with temperature; at 80 to 90 ° C, the nitro group is reduced almost immediately. However, the elevated temperature may cause by-products, for example, hydrolysates. Also, the degree of alkalinity in the reaction mixture can have a greater effect on the formation of impurities. It has been observed that it is advantageous to select a lower temperature at a higher pH and vice versa.

- 3 225 531

For example, the reductions can be carried out by heating the starting compounds of formula II with water to a selected temperature, followed by alternating addition of alkali and ferrous salt. However, the nitro compound can also be mixed with water and alkali and iron salt - preferably only at the reaction temperature · An alternative is also technically feasible when the nitro compound is mixed with water and ferrous salt and alkali is added to this mixture, preferably after heating to the reaction temperature. In the new production process, it is not decisive in which order the components are mixed.

During the reduction, iron oxides are precipitated, which are removed from the final suspension by mechanical separation, for example by filtration, and the resulting salt of the compounds of formula I as a well-soluble substance passes into filtrates from which it is isolated by known methods, for example by acidification with mineral acid or salting out or evaporation and the like.

The advantages of the production method according to the invention are, on the one hand, a reduction in production costs (cheap reducing agent and simple production equipment), and a significant improvement in product quality, since the reducing properties of the iron salts unexpectedly reduced the formation of undesirable impurities.

Example 1

146 g of a paste containing 0.32 mol of 1-amino-4-nitroanthraquinone-2-sulfonic acid are mixed with 2000 ml of 5% aqueous sodium carbonate solution and heated to 40 ° C. A total of 534 g of crystalline ferrous sulphate (PeSO4 · 7H4O) and 422 g of calcined sodium carbonate are then alternately added in small portions so that the pH of the reaction mixture is 8 +0.5; addition time 20 min at 40 ° C. Thereafter, the reaction mixture was heated to 60 ° C to complete the reduction. According to the chromatographic analysis of the obtained suspension, the main constituents are solid iron oxides and dissolved 1,4-diaminoanthraquinone-2-sulfonic acid respectively. its sodium salt and, in addition, 4 unidentified impurities with a total content of about 8 mol%.

1000 ml of water are added to the reaction mixture, the suspension is heated to 65 ° C and the iron oxides are filtered off. The filtrate obtained is a solution of relatively very pure 1,4-diamino anthraquinone-2-sulfonate (Note that there is also a sodium sulphate formed during the reduction). According to the analysis, the filtrate contained 82% of theory; the resulting solution can either be used for further synthesis or the 1,4-diaminoanthraquinone-2-sulfoacid may be isolated in some known manner, for example by salting, evaporation, acidification and the like.

Instead of sodium carbonate, 550 g of potassium carbonate or 320 g of sodium hydroxide or 440 g of potassium hydroxide or 1 120 ml of 25% ammonia or 920 g of crystalline trisodium phosphate (Na2 PO4 · 10 HgO) or 565 g of anhydrous tripotassium phosphate may be used.

Example 2

A solution is prepared from 146 g of paste and 2000 ml of 5% sodium carbonate as in Example 1, and a total of 545 g of 98% green vitriol and 422 g of calcined sodium carbonate are alternately added as in Example 1 at 40 ° C.

A treatment similar to that in Example 1 gives a solution of sodium 1,4-diaminoanthraquinone-2-sulfonate in a yield of 80.5% of theory.

If, instead of 545 g 98% green vitriol, 552 g 96.7% waste green vitriol from titanium dioxide is used, 80.2% of the product theory is obtained.

EXAMPLE 3 1 mol of 1-amino-4-nitroanthraquinone-2-carboxylic acid sodium salt is stirred in 7 l of water, the mixture is heated to 80 DEG C., then 1700 g of green vitriol and 1350 g of calcined sodium carbonate are added. so that the pH of the reaction mixture was 8 + 0.5 $ addition time 30 min at 80 ° C. The mixture was then stirred at 80 ° C for 5 min. The reaction mixture was diluted with 3 L of water and the iron oxides were filtered off at 80 ° C. The filtrate obtained contains:

225,531% of the theory of the 1,4-diaminoantraquinone-2-carboxylic acid product as the sodium salt.

For example, in place of 1,700 g of green vitriol, 990 g of crystalline iron (II) chloride (FeClg · 2 HgO) or 2,400 g of Mohr's salt can be used (NH4 gSO4 · 6 HgOj) or 1,500 g of crystalline acetate. 4 Hgój, the yield and quality of the product are practically the same ·

Example 4

3 g of a condensate prepared from naphthalene-2-sulfonic acid and formaldehyde are added to 2 000 ml of a 5% aqueous sodium carbonate solution and then 146 g of 1-amino-4-nitroanthraquinone-2-sulfonic acid paste containing 0, 2 are added under stirring. A total of 534 g of crystalline ferrous sulphate and 422 g of calcined sodium carbonate are added in portions over 20 minutes in analogy to Example 1. 82.6% of product theory · Example 5

When 3 g of naphthalene-2-sulfonic acid condensate with formaldehyde and 5 ml of isoamyl alcohol are used in place of the reduction described in Example 4, the foaming of the reaction mixture is reduced and the reduction can be carried out within 10 min with virtually the same result.

Claims (3)

SUBJECT OF THE INVENTION 225 531 A process for the preparation of a 1,4-diamino anthraquinone derivative having a solubilizing group in a molecule of formula I wherein X is SO 4 Me or COOMe and Me is hydrogen or a cation, from aminonitroanthraquinones of formula II wherein X is as defined above, a mixture of water, a compound of formula (II), alkali carbonate, hydroxide, phosphate, ammonia, ammonia or mixtures of these alkalis and / or buffers controlling the pH in the range of 7.5 to 12 and the iron salt, optionally in the presence of reducing aids; ° 0 to boiling point · 2. Process according to claim 1, characterized in that the alkali or the ferrous salt or both components are added to the mixture of the other components only after heating to the chosen reaction temperature. 3. A process according to claim 1 or 2, characterized in that green reducing agent is used as reducing agent from chemical products such as titanium dioxide or pickling of metallurgical materials.