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Upstream product

• 14575-62-3 5-methyl-1-phenyl-1,2-dihydro-pyrazol-3-one 
• 14575-62-3 1-phenyl-3-hydroxy-5-methylpyrazole 
• 50877-87-7 1,3-dimethyl-2-phenylpyrazol-5-one 
• 10025-87-3 trichlorophosphate 
• 6112-47-6 5-methyl-1-phenylpyrazolidin-3-one 
• 100-63-0 phenylhydrazine 
• 114-83-0 1-acetyl-2-phenylhydrazine 

Relevant academic research and scientific papers

Strategy to Prepare 3-Bromo- and 3-Chloropyrazoles

A general strategy to prepare substituted 3-bromo- and 3-chloropyrazoles is described. The three-step method involves condensation of crotonates or β-chloro carboxylic acids with hydrazines, followed by halogenation and oxidation. Several condensation and oxidation protocols were developed to enable preparation of a wide variety of 3-halopyrazoles with good to excellent yields and regiocontrol.

Mass Spectrometry of Halo-pyrazolium Salts

Eleven halogen substituted 1-methyl-2-phenylpyrazolium bromides or chlorides were investigated by field desorption, field ionization, and electron impact mass spectrometry.Dealkylation was found to be the predominant thermal decomposition.An exchange between covalent and ionic halogen prior to dealkylation was observed and is discussed in detail.