Amberlyst 15 catalyzed synthesis of indole–pyrazole based tri(hetero)arylmethanes

An expedient synthesis of 1,3-diaryl-4-(3,3′-diindolyl)methylpyrazoles 3a–m has been developed using Amberlyst 15 catalyzed condensation of 1,3-diaryl-4-formyl pyrazoles 2 with indoles 1. This reaction was further extended to the synthesis of 4,4′-bis(3,3′-diindolyl)methylphenoxy-alkanes 5a–b by coupling of 4,4′–di(formylphenoxy)alkane 4 with indole 1.