N-{2-[4-(5-chloro-2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)-1-piperidinyl]-ethyl}-4-fluoro-2-nitrobenzamide → 2-amino-N-{2-[4-(5-chloro-2,3-dihydro-2-oxo-1H-benzimidazol-1yl)-1-piperidinyl]ethyl}-4-fluorobenzamide hydrochloride dihydrate

Participants

Reaction Steps

A mixture of 0.9 parts of N-{2-[4-(5-chloro-2,3-dihydro-2-oxo-1H-benzimidazol-1yl)-1-piperidinyl]ethyl}-4-fluoro-2-nitrobenzamide in 80 parts of methanol is hydrogenated at normal pressure and at room temperature with 1 part of Raney-nickel catalyst. After the calculated amount of hydrogen is taken up, the catalyst is filtered off and the filtrate is evaporated. The residue is converted into the hydrochloride salt in 4-methyl-2-pentanone and 2-propanol. The salt is filtered off and crystallized from a mixture of 2-propanone and water, yielding 0.2 parts of 2-amino-N-{2-[4-(5-chloro-2,3-dihydro-2-oxo-1H-benzimidazol-1yl)-1-piperidinyl]ethyl}-4-fluorobenzamide hydrochloride dihydrate; mp. 250° C.

Provenance & Evidence