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.
成功合成了1,3-二芳基-4-卤代-1H-吡唑。合成涉及3-芳基噻唑酮和2-芳基-1,1-二卤代-1-烯的[3 + 2]双极环加成。该过程在中等至优良的产率下顺利进行。发现1,3-二芳基-4-卤代-1H-吡唑是重要的中间体,可通过Pd催化的C-H键活化轻松转化为1,2,5-三芳基取代的吡唑。