Acetic Acid → 1-Benzyl-2-methyl-5-(5-methyl-3-oxo-4,5-dihydro-2H-6-pyridazinyl)-benzimidazole

Reaction equation

[CH3:1][CH:2]1[C:7]([C:8]2[CH:13]=[CH:12][C:11]([NH:14][CH2:15][C:16]3[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=3)=[C:10]([NH2:22])[CH:9]=2)=[N:6][NH:5][C:4](=[O:23])[CH2:3]1.N.[C:25](O)(=O)[CH3:26]>>[CH2:15]([N:14]1[C:11]2[CH:12]=[CH:13][C:8]([C:7]3[CH:2]([CH3:1])[CH2:3][C:4](=[O:23])[NH:5][N:6]=3)=[CH:9][C:10]=2[N:22]=[C:25]1[CH3:26])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

Reactant 3

HCID 176Acetic Acid

HCID 222Ammonia

HCID 131366765-Methyl-6-(3-amino-4-benzylamino-phenyl)-4,5-dihydro-2H-pyridazine-3-one

Product 1

HCID 205169121-Benzyl-2-methyl-5-(5-methyl-3-oxo-4,5-dihydro-2H-6-pyridazinyl)-benzimidazole

Procedure

The product obtained according to (a) was taken up in 100 ml of glacial acetic acid and refluxed for 2.5 hours. The mixture was mixed with ice and made alkaline with ammonia, and the precipitated product was purified by chromatography on silicagel (eluting agent: at first pure methylene chloride, then increasing amounts of acetone up to a mixture ratio methylene chloride/acetone=10:3). After evaporation, the product was obtained in crystalline form by trituration with ether.