Efficient synthesis of 1,3-diaryl-4-halo-1 H-pyrazoles from 3-arylsydnones and 2-aryl-1,1-dihalo-1-alkenes

Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092, China.
Beilstein Journal of Organic Chemistry (Impact Factor: 2.76). 12/2011; 7:1656-62. DOI: 10.3762/bjoc.7.195
Source: PubMed


An efficient synthesis of 1,3-diaryl-4-halo-1H-pyrazoles was achieved. The synthesis involves the [3 + 2] dipolar cycloaddition of 3-arylsydnones and 2-aryl-1,1-dihalo-1-alkenes. The process proceeds smoothly in moderate to excellent yields. 1,3-Diaryl-4-halo-1H-pyrazoles are found to be important intermediates that can easily be converted into 1,2,5-triaryl-substituted pyrazoles via Pd-catalyzed C-H bond activation.

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