188935-71-9

Upstream product

• 217474-46-9 2,4-Dioxo-3-(phenyl-hydrazono)-4-p-tolyl-butyric acid 
• 103344-69-0 (Z)-2-hydroxy-4-oxo-4-p-tolyl-2-butenoic acid 
• 100-34-5 benzene diazonium chloride 
• 39848-01-6 (Z)-methyl 2-hydroxy-4-(4-methylphenyl)-4-oxobut-2-enoate 
• 67-56-1 methanol 
• 147670-94-8 1-phenyl-3-p-toluoyl-4,5-dihydro-4,5-pyrazoledione 

Relevant academic research and scientific papers

FIVE-MEMBERED 2,3-DIOXOHETEROCYCLES. XXIII. SYNTHESIS OF 1-ARYL-3-AROYL-4,5-DIHYDRO-4,5-PYRAZOLEDIONES AND THEIR REACTION WITH WATER AND ALCOHOLS

4-Aroyl-3-arylhydrazono-2,4-dioxobutyric acids were obtained by the azo coupling of aroylpyruvic acids with arenediazonium salts. Under the influence of thionyl chloride (benzene, 78 deg C, 1.5-4h) they undergo cyclization to 1-aryl-3-aroyl-4,5-dihydro-4,