Method for preparing diazoxide

Abstract

The invention discloses a method for preparing diazoxide. The method comprises the following steps: reacting o-aminobenzenesulfonamide with N-chlorosuccinimide in a chlorine solvent to obtain 2-amino-5-chlorobenzenesulfonamide, mixing the 2-amino-5-chlorobenzenesulfonamide, an imidazolium salt and an amide solvent, and heating the obtained mixture to react to obtain the diazoxide; or mixing o-aminobenzenesulfonamide, the imidazolium salt and the amide solvent, heating for a reaction to obtain a compound IV, and reacting the compound IV with N-chlorosuccinimide in the chlorine solvent so as toobtain the diazoxide. The invention also discloses an application of imidazole hydrochloride as a catalyst in the preparation of diazoxide. The method avoids the problems that chlorosulfonyl isocyanate and strong acid (sulfuric acid) which have high corrosivity and toxicity are used in the reaction process and the reaction temperature is high (240-250 DEG C), and the reaction steps are short; thetotal yield of the two steps can reach 90% or above; and compared with publicly reported diazoxide preparation methods, the synthesis method of the invention overcomes numerous defects, so that the synthesis method is suitable for industrial production.

Description

technical field [0001] The invention belongs to compound preparation technology, in particular to a method for preparing diazoxide. Background technique [0002] Diazoxide is a fast-acting antihypertensive drug. It is a first-aid drug for patients with hypertensive crisis, and it is also used to treat hypoglycemia symptoms caused by hyperinsulinemia, especially the drug of choice for congenital hyperinsulinemia. It is a kind of rare disease drug for infants and young children that is not yet available in China and is urgently needed in clinical practice. Molecular formula: C 8 h 7 ClN 2 o 2 S, alias: chloroxylazine; 7-chloro-3-methyl-2 H -1,2,4-Benzothiadiazine 1,1-dioxide; Hypotensine; 7-Chloro-3-methyl-2hydro-1,2,4-benzothiadiazine 1,1 -Dioxide; CAS number: 364-98-7; structural formula as follows: [0003] [0004] The reported synthetic route of the drug mainly contains the following three synthetic methods: A, B and C: [0005] [0006] [0007] Starting...

AI Technical Summary

Problems solved by technology

Problems in the existing methods: the steps of routes A and B among the three methods are long, and route A requires a three-step reaction. Sulfurisocyanatidic chloride (chlorosulfonyl isocyanate) is used in the process. This reagent is poisonous, extremely active, and water-sensitive. Gas is released, the reaction is violent, the reagent AlCl used in the next step 3 It is also easy to absorb moisture, so the anhydrous conditions of the reaction are strictly required. The final step requires the use of acetic acid, which is processed at a high temperature of 130°C to obtain the final product. Acetic acid is highly volatile, irritating and corrosive; route B requires four steps to obtain The final product, the first two steps are the same as route A, and then in strong acid H 2 SO 4 After the treatment, the ring is opened, and then triethyl orthoacetate is used for ring-closing reaction to obtain the product. Compared with the above route A, this route has one more step of reaction, and uses strong corrosive sulfuric acid; route C requires an acid-binding agent and high temperature closed loop

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