SU1265190A1 - Method of isolating 1,5-dioxyanthraquinone - Google Patents

Abstract

METHOD OF EXAMPLE OF 1,5-DIOXIANTHRAHINON from a mixture of dimethoxy- or dioxyanthraquinones by selectively sulphonating the mixture at elevated temperature followed by diluting the reaction mass with water, characterized in that, in order to reduce the duration of the process, increase the yield and improve the quality of the target product, sulfonation is carried out with sulfuric acid concentration of 100-104.5% in the presence of boric acid with a mass ratio of the mixture and boric acid equal to 1: 0.25-0.45.

Description

This invention relates to an improved process for isolating individual 1,5-dioxyanthraquinone from a mixture of dimethoxy- or dioxyanthraquinones, an important product for the synthesis of high-strength dyes. The aim of the invention is to reduce the duration of the process, increasing the yield and quality of the target product. Example I. South of the mixture of dioxyanthraquinone isomers (DOA) (1.5 isomer 48.8%, 1,. 8 isomer 35.3%, other isomers I5.9%) are filled with 120 g of 100% sulfuric acid (ratio 1: 12) and 2.5 g of boric acid (1: 0.25 ratio) for 6 hours at 150 ° C. Cool the reaction mixture to 70 ° C and dilute with 51 ml of water to 70% sulfuric acid. After cooling to 50 seconds and stirring for 1 hour, the precipitate is filtered off, washed with water to neutral medium over congo paper and dried at 100 ° C. 4.95 g of 1.5-DOA, mass fraction of the main substance, 96.2% are obtained, the yield is 97.6%, calculated on the loaded 1.5-DOA. Example 2. South of the DOA mixture (1,5-isomer 48.8%, 1,8-isomer 35.3%, other isomers 15.9%), containing 90 g of 104.5% sulfuric acid (ratio 1 : 9) and 4.5 g of boric acid (ratio 1: 0.45) for 6.5 h at 120 s. Cool the reaction to 60 ° C and dilute with 27.5 ml of water to 80% sulfuric acid. After cooling to 40 ° C and stirring for 0.5 h, the precipitate is filtered off and washed with water until neutral with congo paper. 4.9 g of 1.5-DOA are obtained, dried at 50 ° C. with a mass fraction of the main substance of 97.5% and output of the house of 98.0%, considering the original. Example 3. South of the DOA mixture (1,5-isomer 60%, 1,8-isomer 40%) is kept with 110 g of 102.5% sulfuric acid (1:11 ratio) and 3.5 g of boric acid (ratio 1: 0.35) 8 h at SO ° C. After cooling, it is diluted with 40 ml of water to 75% sulfuric acid. Cool the reaction mass before and after aging at this temperature for 1 h, filter the precipitated precipitate and rinse it with water until neutral for congo paper and dry at 100 ° C. 6.11 g of 1.5-DOA are obtained with a mass fraction of the basic substance 98, 8% and 902 yields of 99.4%, based on the original 1,5-DOA. Example 4. South of the mixture of isomers of dimethoxyanthraquinones (DMA) (1.5 isomer 49%, 1.8 isomer 42.5%, other isomers 8.5%) is maintained with 100 g of Yu3% sulfuric acid (1:10 ratio) and 3 g of boric acid (1: 0.3 ratio) 1.5 h at. Cool, cool to 60 ° C and dilute the reaction mass with 37 ml of water to 75% sulfuric acid. After cooling to 50 ° C and stirring at this temperature for 1 hour, the precipitate is filtered, washed with neutral water on Congo paper and dried at SO. ° C. 4.37 g of 1.5-DOA are obtained with a mass fraction of the basic substance of 98.7% and a yield of 98.4%, calculated on the loaded 1.5-DMA. Example 5. A mixture of DMA (1,5-isomer 50%, 1,8-isomer 50%) is contained in 120 g of Yu1.5% sulfuric acid (1:12 ratio) and 4 g of boric acid (ratio 1: 0.4) 4.5 hours at. The reaction mass is cooled to 70 ° C and diluted with 54 ml of water to 70% sulfuric acid. After cooling to 40 ° C and stirring for -0.5 h, the precipitate is filtered off, washed with water to neutral medium over congo paper and dried at HU ° C. 4.47 g of 1E5-DOA are obtained with a mass fraction of the main substance of .97.9% and a yield of 97.8%, based on the starting 1.5-DMA. Example 6. South of the mixture of DMA (155-isomer 47.7%, 1,8-isomer 38.2% other isomers 14.1%) is maintained with 90 g of 103.5% sulfuric acid (1: 9 ratio) and 3.5 g of boric acid (1: 0.35 ratio) 0.5 h at 150 ° C. The reaction mass is cooled to and diluted with 26 ml of water to 80% sulfuric acid. After cooling to 45 ° C. and stirring at this temperature for 1.5 hours, the precipitate is filtered and washed with water until neutral over congo paper. Dried at. 4.3 g of 1.5-DOA with a mass fraction of the main substance of 97.8% and a yield of 98.6% are obtained, calculated on the loaded 1.5-DMA. About Example 7 (compare), Yu g of the mixture of DOA (1 , 5-isomer 60%, "1,8-isomer 40%) is kept at 110 g of 102.5% sulfuric acid and 5 g of boric acid (1: 0.5 ratio) for 8 hours at, After cooling to 65 ° WITH

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diluted with 40 ml of water to 75% sulfuric acid. Cool the reaction mass to 40 ° C and after settling at this temperature, the precipitated precipitate is filtered off for 1 h, washed with water until neutral over congo paper and dried at 100 °. 6.05 g of 1.5-discianthraquinone is obtained with a mass fraction of the basic substance 98 , 2% and a yield of 99.1%, based on the original 1,5-DOA.

Example 8 (comparative). 10 g of a mixture of DMA (1-, 5-isomer 49%, 1, -8 isomer 42.5%, other isomers 8.5%) are contained with 100 g of 103% sulfuric acid and 2 g of boric acid (1: 0 ratio , 2) 1 hour at 140 ° C. Cool to 60 ° C and dilute the reaction mass with 37 ml of water to 75% sulfuric acid. After cooling to 50 ° C and stirring at this temperature for 1 h, the precipitate is filtered off, washed with water until neutral medium on Congo paper and suc1904

Shat at 100 ° C. 4.01 g of 1.5-DOA are obtained with a mass fraction of the basic substance of 92.4% and a yield of 84.5%, calculated on the initial 1.5-DMA,

Thus, when the mass ratio of the mixture and boric acid is less than 1: 0.25, undesirable sulfonation takes place, which leads to a decrease in the yield and quality of the target product. Using a ratio greater than 1: 0.45 is uneconomical, since boric acid is sufficient for binding the 1,5-isomer.

The use of sulfuric acid below 100% is undesirable due to the duration of the process, and with a concentration of more than 104.5% due to the formation of by-products.

The proposed method allows to speed up the process of obtaining 1,5-DOA (0.5-8 h) with a simultaneous increase in the yield of the target product (97.699, 4%) and the mass fraction of the basic substance (96.2-98.8%).

Claims (1)

METHOD FOR ISOLATING 1,5-DIOXYANTHRACHINONE from a mixture of dimethoxy- or • dioxoanthraquinone by selective sulfonation of the mixture at elevated temperature followed by dilution of the reaction mass with water, characterized in that, in order to reduce the duration of the process, increase the yield and improve the quality of the target product, sulfonation is carried out with sulfuric acid a concentration of 100-104.5% in the presence of boric acid with a mass ratio of the mixture and boric acid equal to 1: 025-0.45. _from SS MA A 05 JV with O