DIHALOGENATIVE CYCLIZATION FOR THE SYNTHESIS OF 4-BROMO-1-BROMOALKYL-5-ARYL/ALKYL/ALKENYL-PYRAZOLES

A copper-mediated domino reaction involving cyclization, bromination, and nucleophilic substitution of N,N-disubstituted hydrazones, which are labile under oxidative conditions, to synthesize 4-bromo- 1-bromoalkyl-5-aryl/alkyl/alkenyl-pyrazoles, is achieved. This method features the simultaneous construction of pyrazoles and two C-Br bonds, which are synthetically useful.

Automated summary

A copper-mediated domino reaction has been developed for the synthesis of 4-bromo-1-bromoalkyl-5-aryl/alkyl/alkenyl-pyrazoles from N,N-disubstituted hydrazones. This method allows for the simultaneous construction of pyrazoles and two C-Br bonds, offering synthetic utility.