[NH2:1][C:2]1[CH:3]=[C:4]([C:12]#[N:13])[C:5]2[N:9]=[CH:8][NH:7][C:6]=2[C:10]=1[CH3:11].CS[C:16]1[N:17]([C:21]([O:23][CH3:24])=[O:22])[CH2:18][CH2:19][N:20]=1.[OH-].[Na+]>C(O)(=O)C>[CH3:24][O:23][C:21]([N:17]1[CH2:18][CH2:19][NH:20][C:16]1=[N:1][C:2]1[CH:3]=[C:4]([C:12]#[N:13])[C:5]2[NH:9][CH:8]=[N:7][C:6]=2[C:10]=1[CH3:11])=[O:22]A mixture of 6-Amino-7-methyl-1H-benzimidazole-4-carbonitrile (10) (22.3 g, 0.13 mol), 4,5-dihydro-2-(methylthio)-1H-imidazole-1-carboxylic acid, methyl ester (29) (27.1 g, 0.155 mol) and glacial acetic acid (223 mL) is heated to about 85° C. for about 3 hours. The reaction mixture is allowed to cool to ambient temperature and is then concentrated in vacuo. At ambient temperature, water (223 mL) is then added to the oily residue obtained, and the pH of the resultant solution is adjusted to about 8.1 with 6N aqueous NaOH. The solids that formed are filtered, washed with water (75 mL), and dried to provide 2-(7-Cyano-4-methyl-1H-benzimidazol-5-yl-imino)-imidazolidine-1-carboxylic Acid Methyl Ester (30) (29.1 g, 75% Yield), as an off-white solid.
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