[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([O:8][CH3:9])=[CH:4][C:3]=1[NH:10][C:11]([NH:13][CH:14]1[CH2:19][CH2:18][N:17]([CH3:20])[CH2:16][CH2:15]1)=S>[Hg]=O.O1CCCC1>[CH3:9][O:8][C:5]1[CH:6]=[CH:7][C:2]2[NH:1][C:11]([NH:13][CH:14]3[CH2:19][CH2:18][N:17]([CH3:20])[CH2:16][CH2:15]3)=[N:10][C:3]=2[CH:4]=1A mixture of 44 parts of N-(2-amino-5-methoxyphenyl)-N'-(1-methyl-4-piperidinyl)thiourea, 38.9 parts of mercury(II) oxide and 270 parts of tetrahydrofuran was stirred and refluxed for 2 hours at reflux temperature. The reaction mixture was filtered while hot over diatomaceous earth and the filtrate was evaporated. The residue was purified by column chromatography over silica gel first using a mixture of trichloromethane and methanol (95:5 by volume) and then a mixture of trichloromethane and methanol, saturated with ammonia, (85:15 by volume) as eluents. The pure fractions were collected and the eluent was evaporated, yielding 50.5 parts (100%) of 5-methoxy-N-(1-methyl-4-piperidinyl)-1H-benzimidazol-2-amine as a residue (interm. 27).
Wird geladen…