A mild and efficient method for halogenation of 3,5-dimethyl pyrazoles by ultrasound irradiation using N-halosuccinimides
The 4-halo-3,5-dimethyl pyrazoles have been synthetisized in good yields in short reaction times in the absence of a catalyst by reaction of 3,5-dimethyl pyrazoles with N-halosuccinimides (NBS, NCS and NIS) under ultrasound irradiation. Finally, the halogenation of pyrazoles with Br2, IC1 and I2 was showed in similar conditions.
Stefani, Hélio A.,Pereira, Claudio M. P.,Almeida, Roberta B.,Braga, Rodolpho C.,Guzen, Karla P.,Cella, Rodrigo