Acetic Acid → N-[1-[2-(2-pyrazinyl)ethyl]-4-piperidinyl]-1H-benzimidazol-2-amine

Reaction equation

[CH:1]([C:3]1[CH:8]=[N:7][CH:6]=[CH:5][N:4]=1)=[CH2:2].FC1C=CC(C[N:17]2[C:21]3[CH:22]=[CH:23][CH:24]=[CH:25][C:20]=3[N:19]=[C:18]2[NH:26][CH:27]2[CH2:32][CH2:31][NH:30][CH2:29][CH2:28]2)=CC=1.C(O)(=O)C>CO>[N:4]1[CH:5]=[CH:6][N:7]=[CH:8][C:3]=1[CH2:1][CH2:2][N:30]1[CH2:29][CH2:28][CH:27]([NH:26][C:18]2[NH:17][C:21]3[CH:22]=[CH:23][CH:24]=[CH:25][C:20]=3[N:19]=2)[CH2:32][CH2:31]1

Participants

Procedure

A mixture of 1.27 parts of 2ethenylpyrazine, 6.48 parts of 1-[(4 fluorophenyl)methyl]-N-(4-piperidinyl)-1H-benzimidazol-2-amine, 0.3 parts of acetic acid and 40 parts of methanol was stirred and refluxed for 48 hours. The solvent was evaporated. The residue was purified by column-chromatography over silica gel using a mixture of trichloromethane and methanol (88:12 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was washed with 2,2'-oxybispropane and crystallized from 27 parts of methylbenzene, yielding 2.4 parts of 1-)4-fluorophenylmethyl)-N-[1-[2-(2-pyrazinyl)ethyl]-4-piperidinyl]-1H-benzimidazol-2-amine; mp. 165.3° C. (compound 101).