Vilsmeier reaction between 2,4-dimethylpyrrole (I) and dimethylformamide (II) by means of phosphorous oxychloride in dichloroethane provides carbaldehyde (III), which is then condensed with 2-indolinone (IV) in ethanol in the presence of piperidine.
Title compound was prepared by condensation of oxindole (I) and formylpyrrole (II) in the presence of a catalytic amount of piperidine in refluxing EtOH.
The reaction of 1-phenylpiperazine (I) with DMF and POCl3 in dichloroethane gives 4-(4-formylpiperazin-1-yl)benzaldehyde (II), which is condensed with indolin-2-one (III) by means of piperidine in refluxing ethanol.
Aldehyde (II) was prepared by Vilsmeier-Haack formylation of 2,4-dimethylpyrrole (I). Subsequent condensation of the pyrrole aldehyde (II) with 5-chlorooxindole (III) in the presence of piperidine furnished the title compound.