The invention relates to a method for preparing
bilastine. The method comprises the following steps: adding a compound I oxazolol to water, adding a
phase transfer catalyst, p-toluenesulfonyl chlorideand
sodium hydroxide, stirring and reacting all above substances, and performing
filtration to obtain oxazolol
sulfonate; adding the
sulfonate to water, adding 2-(4-piperidinyl)-1-H-
benzimidazole andthe
phase transfer catalyst, adding
sodium carbonate or
potassium carbonate, heating the obtained suspension, performing a reaction for 3-5 h, filtering the obtained intermediate II, adding the intermediate II to a strong polar aprotic
solvent, adding
sodium hydroxide and the
phase transfer catalyst, adding
ethylene glycol monoethyl
ether tosylate, stirring and reacting the obtained mixture at -20-60 DEG C, filtering the obtained
reaction product, and washing the filtered
reaction product with water to obtain an intermediate III; and adding the intermediate III to an
aqueous solution of an
organic acid, performing refluxing for 3-5 h, adding water, adding a strong alkali until saturation, refluxing the obtained solution for 3-5 h to generate a
bilastine salt insoluble in the saturated alkaline solution, and performing extraction to obtain the
bilastine. The method has the advantages of mild
reaction conditions, simplicity in operation, greenness,
environmental protection, high yield,and convenience in industrial production.