反应详情

A mixture of 36.6 parts of N-(4-piperidinyl)-1H-benzimidazol-2-amine dihydrobromide, 10 parts of poly(oxymethylene), 2 parts of a solution of thiophene in methanol 4%, 200 parts of methanol and 20 parts of potassium hydroxide was hydrogenated at normal pressure and at room temperature with 4 parts of palladium-on-charcoal catalyst 10%. After the calculated amount of hydrogen was taken up, the catalyst was filtered off and the filtrate was evaporated. The residue was treated with a sodium hydroxide solution. The precipitated product was filtered off and dried, yielding 13.7 parts (59.4%) of N-(1-methyl-4-piperidinyl)-1H-benzimidazol-2-amine (interm 30).

1. filtrationthe catalyst was filtered off
2. customthe filtrate was evaporated
3. additionThe residue was treated with a sodium hydroxide solution
4. filtrationThe precipitated product was filtered off
5. customdried