Improvement On Albendazol Manufacturing Process

Albendazol is a wide-spectrum, high-efficient and harmfulless antiparasitic drug. In this text, the traditional processes of its synthesis and purification were improved. As a result, the high-quality Albendazol in accord with Smith Kline company (USA) specification was manufactured.In the synthesis process, carbendazim was adopted as main raw material to perform chlorosulfonation with chlorosulfonic acid, then iron powder was added for reduction, bromopropane was added for etherification. In the end, toluene was add for deodorization. The obtained Albendazol crude is almost white powder, no order, with the purity up to 98.0% above.The salification process of Albendazole with acetone hydrochloride was improved and the impurities were separated. Meantime the stability of Albendazol in acetone hydrochloride was examined. The results showed that the impurity F rise clearly and the impurity F can be prevented effectively under the control of salification time of acetone.The decolourization and purification processes of Albendazol in the methanol hydrochloride solution were investigated. The results indicated the hydrolysis of Albendazol can be prevented effectively. The assay of Albendazol showed much ammonium chloride and methanol in the products, so the purification process is abandoned.The decolourization and purification processes of Albendazol in the hydrochloric acid solution were inveatigated. The stability of Albendazol in the hydrochloric acid solution was also examined. The impurity A increasing clearly showed the evidence of hydrolysis. The hydrolysis can be prevented effectively by the method of controlling the time of decolourization and filtration, washing with heat water and alcohol, then drying. There are little ammonium chloride and methanol. The assay of Albendazole is up to 99.0% above. The purification process is adopted in the production.The process is very simple, raw materials are available easily, the yield is up to 56%. The product is up to international advanced level. It can be applied in industrial production widely.