SU1525143A1 - Method of obtaining 1,3-dihydroxy-2-hydromethylanthraquinones - Google Patents

Abstract

This invention relates to anthraquinone derivatives, in particular the preparation of 1,3-dihydroxy-2-hydroxymethyl-anthraquinone, which can be used in the preparation of biologically active compounds. The goal is to simplify the process technology and increase the yield of the target product. It is prepared by hydroxymethylation of an alkaline solution of 1,3-dihydroxyanthraquinone with an aqueous solution of formaldehyde at a molar ratio of 1: 8 and at room temperature. The process is carried out in a 3-10% solution of potassium carbonate. The formaldehyde solution is introduced into the reaction volume in two steps: half at the beginning of the reaction and the remaining half in 6-8 hours. Yield 94 versus 70% in the known process.

Description

The invention relates to an improved process for the preparation of 1, 3-dihydroxy-2-hydroxymethylanthraquinone, which can be used in the preparation of biologically active compounds.

The purpose of the invention is to simplify the process technology and increase the yield of the target product.

Example 1. 0.005 mol (1.2 g) of 1,3-dihydroxyanthraquinone B dissolve 180 ml of 3% potassium carbonate solution, while 1.5 ml of 40% formaldehyde solution is added dropwise with stirring (0.02 mole) and leave the reaction mixture at room temperature. After 6 hours, add 1.5 ml of 40% dropwise with stirring.

formaldehyde solution (0.02 mol) and left for 6-10 hours. The progress of the reaction is monitored by chromatography in a thin layer of sorbent. The yield of the target product is 1.21 g (89%),

Example 2. 0.005 mol (1.2 g) of 1,3-dihydroxyanthraquinone is dissolved in 60 ml of a 10% potassium carbonate solution, and 1.5 ml of a 40% formaldehyde solution (0.02 g) is added dropwise with stirring. mole) and leave the reaction mixture at room temperature. After 6 hours, another 1.5 ml of 40% formaldehyde solution (0.02 mol) was added dropwise with stirring and left to stand at 6-tO h. The reaction was monitored by chromatography in a thin layer of sorbent. The yield of the target product 1.23 g (91Z),

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Example 3. 0.005 mol (1.2 g of 1,3-dihydroxyanthraquinone is dissolved in 60 MP of 5% potassium carbonate solution, while stirring, 1.5 ml of A0% formalin solution is added dropwise (0.02 mol ) and leave the reaction mixture at room temperature. After 6 hours, another 1.5 ml of A0% formaldehyde solution (0.02 mol) is added dropwise with stirring and left for 6-10 hours. by chromatography in a thin layer of sorbent. The yield of the target product is 1.28 g (94%).

When using a potash solution with a concentration below 3%, the initial alkaline solution is obtained too dilute, which leads to an additional loss of the desired product. When using a potash solution with a concentration above 10%, along with the target product, by-products are also formed, which complicates the purification process of the target product.

Thus, the proposed method allows to increase the yield of the target product from 70 by the known

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method up to 94% of the proposed. The simplification of the technology in the proposed method is achieved by carrying out the process at room temperature and reducing the number of stages.

Claims (1)

Invention Formula The method of producing 1,3-dihydroxy-2-hydroxymethyl-anthraquinone by hydroxymethylation of an alkaline solution of an anthraquinone dihydroxy derivative with an aqueous formaldehyde solution, characterized in that, in order to simplify the process technology and increase the yield of the target product, dihydroxy anthraquinone is used in 3-dihydroxydids, and it is used in 3 dihydroxydes and 1,3-dihydroxydide, which is used to increase the yield of the target product, as a dihydroxy derivative of anthraquinone, it is used to use 1.3-dihydroxydibide, dihydroxy dihydroxydes and 1,3-dihydroxydibenes are used to increase the yield of the target product. , hydroxymethylation is carried out in a 3-10% solution of potassium carbonate at room temperature at a molar ratio of 1,3-dihydroxyanthraquinone: formaldehyde, equal to 1: 8, and the solution Formaldehyde is introduced into the reaction volume in two steps: one half at the beginning of the reaction and one half after 6–8 h.