Albendazole (CAS NO.: 54965-21-8), with other name of N-(5-Propylsulfanyl)benzimidazole-2-ylcarbamic acid methyl ester, could be produced through many synthetic methods.

Following is one of the synthesis routes:
3-Chloro-6-nitroacetanilide (I) is condensed with propylmercaptane (A) in the presence of aqueous refluxing NaOH to produce 2-nitro-5-propylthioaniline (II), which was reduced with H₂ over Pd/C in ethanol HCl to afford 4-propylthio-o-phenylenediamine (III). The cyclization of (III) with cyanogen bromide affords 2-amino-5-propylthiobenzimidazole (IV), which is finally condensed with methyl chloroformate. It can be condensed directly with a mixture of cyanamide and methyl chloroformate or with carbomethoxycyanamide (B). All these condensations are performed in basic medium.