5-Amino-2-benzimidazolethiol

Compounds with a benzimidazole structure, led by omeprazole, can inhibit the acid secretion of gastric parietal cells induced by any stimulus, thus inhibiting the final step of gastric acid being pumped from the parietal cells into the gastric lumen, and therefore have the best therapeutic effect. 5-Amino-2-mercaptobenzimidazole, as an important starting material or intermediate for this type of drug, has a huge market demand.

off-white to light yellow crystalline powder

Dissolve 2-mercapto-5-nitrobenzimidazole in methanol, ethanol, dichloromethane, trichloromethane or tetrahydrofuran and add 5-20 equivalents of zinc powder in batches. Concentrated hydrochloric acid is slowly added to the mixture until said mixture is colorless. At the end of the reaction, the insoluble material is removed by filtration, and the filtrate is adjusted to pH=9-10 by adding saturated potassium carbonate solution. activated carbon is added to decolorize the reaction, and the reaction continues to be heated and refluxed for 0.5-2 h. The reaction is filtered through diatomaceous earth, and dried to obtain a yellow solid of 5-amino-2-mercaptobenzimidazole.