2,3-Dimethyl-8-(2,4-dichlorophenyl)-5,6-dihydroimidazo[1,2-a]pyridine → 2,3-Dimethyl-8-(2,4-dichlorophenyl)imidazo[1,2-a]pyridine
Reaction equation
[CH3:1][C:2]1[N:3]=[C:4]2[C:9]([C:10]3[CH:15]=[CH:14][C:13]([Cl:16])=[CH:12][C:11]=3[Cl:17])=[CH:8][CH2:7][CH2:6][N:5]2[C:18]=1[CH3:19]>C(Cl)Cl.[O-2].[O-2].[Mn+4]>[CH3:1][C:2]1[N:3]=[C:4]2[C:9]([C:10]3[CH:15]=[CH:14][C:13]([Cl:16])=[CH:12][C:11]=3[Cl:17])=[CH:8][CH:7]=[CH:6][N:5]2[C:18]=1[CH3:19]Participants
4
Procedure
2,3-Dimethyl-8-(2,4-dichlorophenyl)-5,6-dihydroimidazo[1,2-a]pyridine (3) (29.3 g, 0.1 mol) is dissolved in methylene chloride (1 L) and activated manganese dioxide (120 g) is added. The mixture is heated at reflux for 16 hours with stirring. The catalyst is removed by filtration of the reaction through a Celite pad and the filtrate is evaporated to a solid (4).