To 1 part of a solution of 2 parts of thiophene in 40 parts of ethanol were added 11.3 parts of 1-(4-fluorophenylmethyl)-N-[1-[2-[(phenylmethyl)amino]ethyl]-4-piperidinyl]-1H-benzimidazol-2-amine, 2 parts of paraformaldehyde, 10 parts of potassium acetate and 120 parts of methanol. The whole was hydrogenated at normal pressure and at room temperature with 2 parts of platinum-on-charcoal catalyst 10%. After the calculated amount of hydrogen was taken up, the catalyst was filtered off over Hyflo and the filtrate was evaporated, yielding 9.4 parts of 1-[(4-fluorophenyl)methyl]-N-[1-[2-(methyl(phenylmethyl)amino]ethyl]-4-piperidinyl]-1H-benzimidazol-2-amine as a residue (intermediate 135).
