A synthesis method for 4,6-dihydroxy quinoline-5,8-diquinone-2-formic acid medicine intermediate

Abstract

The invention discloses a synthesis method for 4,6-dihydroxy quinoline-5,8-diquinone-2-formic acid medicine intermediate including the following steps: adding 4,6-dihydroxy-5,8-dimethoxy-quinoline-2-formic acid and an octane solution into a reaction container, raising the temperature, adding potassium persulfate in batches, controlling the stirring speed, adding an aqueous solution, and continuingthe reaction; adding cadmium nitrate powder, rising the solution temperature, adding potassium sulfate solution, continuing the reaction, reducing the temperature, standing, allowing layering of thesolution, adding a sodium chloride solution to wash multiple times and adding a methyl ether solution to wash multiple times, recrystallizing in an o-chlorotoluene solution, performing dehydration with a dehydrating agent, and obtaining the finished product of the 4,6-dihydroxy quinoline-5,8-diquinone-2-formic acid.

Description

technical field [0001] The invention relates to a preparation method of a pharmaceutical intermediate, belonging to the field of organic synthesis, in particular to a synthesis method of a 4,6-dihydroxyquinoline-5,8-diquinone-2-carboxylic acid pharmaceutical intermediate. Background technique [0002] 4,6-dihydroxyquinoline-5,8-diquinone-2-carboxylic acid is mainly used as an intermediate of leukotine, and most of the existing synthetic methods use 4,5,6,8-tetrahydroxyquinoline-2- Formic acid hydrobromide, sodium bicarbonate, potassium ferricyanide, hydrochloric acid and other reaction raw materials are synthesized. The potassium ferricyanide solution used in this synthesis method can be decomposed by acid and acid salt, releasing highly toxic hydrogen cyanide gas. It decomposes into extremely toxic potassium cyanide at high temperature, which is harmful to the health of synthesis operators. Potassium ferricyanide can be reduced to potassium ferrocyanide by light and reducin...

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Problems solved by technology

[0002] 4,6-dihydroxyquinoline-5,8-diquinone-2-carboxylic acid is mainly used as an intermediate of leukotine, and most of the existing synthetic methods use 4,5,6,8-tetrahydroxyquinoline-2- Formic acid hydrobromide, sodium bicarbonate, potassium ferricyanide, hydrochloric acid and other reaction raw materials are synthesized. The potassium ferricyanide solution used in this synthesis method can be decomposed by acid and acid salt, releasing highly toxic hydrogen cyanide gas. It decomposes into extremely toxic potassium cyanide at high temperature, which is harmful to the health of synthesis operators. Potassium ferricyanide can be reduced to potassium ferrocyanide by light and reducing agents, resulting in loss of raw materials and affecting the final yield and product quality.

Hydrochloric acid as a reactant is highly irritating and can seriously irritate the eyes and mucous membranes of the respiratory tract. Short-term exposure may cause sore throat, coughing, and suffocation. High concentrations may cause laryngospasm and pulmonary edema, thereby endangering the health of production operators; Moreover, hydrochloric acid solution is highly corrosive and requires high corrosion resistance of production equipment, resulting in increased manufacturing costs of production equipment, which is not conducive to reducing reaction costs

Above-mentioned these factors all can cause this synthetic method to have deficiency, therefore be necessary to propose a kind of new synthetic method

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