Bilastine purifying method

Abstract

The invention provides a method for refining and purifying 4-[2-[4-[1-(2-ethoxyethyl)-1H-benzimidazole-2-yl]-1-piperidine]ethyl]-alpha, alpha-dimethyl phenylacetic acid (Bilastine). Bilastine is used for treating allergic rhinitis and chronic idiopathic urticaria, has good safety and does not have the sedative effect and cardiac toxicity of common antihistamine drugs. In most of Bilastine preparation processes, the impurity content is high, and stubborn impurities are difficult to remove. The method for refining and purifying Bilastine, provided by the invention, comprises the steps of dissolving a crude product of Bilastine into a hot mixed solvent, cooling, precipitating, filtering, washing and drying to obtain high-purity Bilastine, wherein the impurity content meets the requirements.

Description

technical field [0001] The invention belongs to the field of medicinal chemistry and provides a 4-[2-[4-[1-(2-ethoxyethyl)-1 H -Benzimidazol-2-yl]-1-piperidine]ethyl]-α,α-Dimethylphenylacetic acid (hereinafter referred to as Bilastine) purification method. Background technique [0002] Bilastine is the second generation of histamine H developed by Spanish FAES pharmaceutical company 1 Receptor antagonist, approved by the European Union for the treatment of allergic rhinitis and chronic idiopathic urticaria in 2010; at the same time, a phase II clinical study was conducted in the United States to investigate its efficacy on seasonal allergic rhino-conjunctivitis. Studies in healthy subjects and patients with rhinitis have shown that this product is safe, without the sedative effect and cardiotoxicity of commonly used antihistamines. [0003] The chemical structural formula of this product: [0004] [0005] Generally speaking, the total impurity content of a drug shoul...

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Problems solved by technology

[0005] Generally speaking, the total content of a drug impurity should be less than 0.3%, and the content of a single impurity should be less than 0.1%; however, in the process of preparing Bilastine in the laboratory, according to the patent The product prepared by the method of US5322850A has too high impurity content, containing more than 0.3% undesired impurities, wherein some recalcitrant impurities cannot be effectively removed by literature methods

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