Читать книгу Routes to Essential Medicines - Peter J. Harrington - Страница 18

Anti‐Infective Medicines/Anthelmintics/Antifilarials

A benzimidazole is often formed from a 1,2‐phenylenediamine.

Discussion. The benzimidazole is formed in the final step from the benzene‐1,2‐diamine and N‐methoxycarbonylcyanamide. N‐Methoxycarbonylcyanamide is formed from cyanamide and methyl chloroformate. 4‐(Propylthio)benzene‐1,2‐diamine is formed by reduction of 2‐nitro‐4‐propylthioaniline. A C─S bond is formed by displacement of chloride from 4‐chloro‐2‐nitroacetanilide by sodium propanethiolate. The acetanilide is also hydrolyzed under the chloride displacement reaction conditions. 4‐Chloro‐2‐nitroacetanilide is formed from 4‐chloro‐2‐nitroaniline and acetic anhydride.