Preparation method of dapsone

Abstract

The invention discloses a preparation method of dapsone, and more in particular relates to a method for preparing dapsone by a one-pot method. The preparation method of dapsone is characterized by comprising the steps of: by taking nitrobenzenesulfonyl chloride as the raw material and methanol as the solvent, and carrying out a desulfurizing coupling reaction under the action of copper acetate to obtain para-dinitrophenyl sulfone, and then adding sodium hydrosulfite to the reaction system to obtain the dapsone. According to the invention, the methanol is taken as the solvent, and sodium hydrosulfite is added as the reducing agent to obtain the dapsone by the one-pot method under the action of the copper acetate without any ligand, the protection of an inert gases and separation; and the total yield can be 88%.

Description

Technical field: [0001] The present invention relates to a kind of preparation method of dapsone, more specifically relate to a kind of method for preparing dapsone by one-pot method. Background technique: [0002] Dapsone (DDS) is a sulfone antibacterial drug that has a strong antibacterial effect on Bacillus leprae, and its preparations have been widely used in the treatment of leprosy [1-2]. As the drug of choice for the treatment of leprosy, it acts on bacterial dihydrofolate synthase (DHPs), interferes with the synthesis of folic acid, and affects the synthesis of proteins by bacteria. In addition, the drug also has an anti-inflammatory effect, and has a significant scavenging effect on toxic oxygen free radicals and other substances produced by neutrophils after being stimulated. At the same time, it can also inhibit the aggregation and activation of neutrophils and reduce inflammatory mediators. release, thereby reducing damage to the body [3]. In recent years, stud...

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Problems solved by technology

[0005] In the above synthesis process: route (1) uses p-acetamidobenzenesulfonyl chloride as a raw material, which is prepared by reacting with acetanilide Friedel-Crafts to obtain acetaminophen sulfone and then hydrolyzing it. The raw materials used are expensive and require a large amount of aluminum trichloride[ 5]; route (2) has simple steps and high yield, but requires pressurized ammoniation and requires high equipment [6]; route (3) has low cost, but uses a protecting group strategy and the steps are cumbersome[7] ], which was improved by pathway (4) using sodium perborate oxidation, but the overall yield was not very high [8]

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