590410-64-3

Basic information

• Product Name: Methanone, (5-hydroxy-1-phenyl-1H-pyrazol-4-yl)phenyl-
• CAS NO: 590410-64-3
• Molecular Formula: C16H12N2O2
• Molecular Weight: 264.283
• Mol File: 590410-64-3.mol
• Article Data: 1

Chemical Properties

• CAS DataBase Reference: Methanone, (5-hydroxy-1-phenyl-1H-pyrazol-4-yl)phenyl-(CAS DataBase Reference)
• NIST Chemistry Reference: Methanone, (5-hydroxy-1-phenyl-1H-pyrazol-4-yl)phenyl-(590410-64-3)
• EPA Substance Registry System: Methanone, (5-hydroxy-1-phenyl-1H-pyrazol-4-yl)phenyl-(590410-64-3)

Safety Data

• Hazardous Substances Data: 590410-64-3(Hazardous Substances Data)

Upstream product

• 98-88-4 benzoyl chloride 
• 876-93-7 1-phenyl-5-hydroxypyrazole 

Downstream Products

• 590410-58-5 (E)-(5-chloro-1-phenyl-1H-pyrazol-4-yl)phenylmethanone oxime 
• 900810-71-1 4-benzoyl-1-oxiranylmethyl-2-phenyl-1,2-dihydropyrazol-3-one 
• 590410-53-0 (5-chloro-1-phenyl-1H-pyrazol-4-yl)phenylmethanone 

Relevant articles and documents

On the tautomerism of pyrazolones: The geminal 2J[pyrazole C-4,H-3(5)] spin coupling constant as a diagnostic tool

The tautomerism of pyrazolones unsubstituted at position 3(5) has been investigated by 13C- and 1H NMR spectroscopic methods. Apart from chemical shift considerations and NOE effects the magnitude of the geminal 2J[pyrazole C-4,H3(5)] spin coupling constant permits the unambiguous differentiation between 1H-pyrazol-5-ol (OH) and 1,2-dihydro-3H-pyrazol-3-one (NH) forms. Whereas 1H-pyrazol-5-ols and 2,4-dihydro-3H-pyrazol-3-ones (CH-form) exhibit 2J values of approximately 9-11 Hz, in 1,2-dihydro-3H-pyrazol-3-ones this coupling constant is considerably reduced to 4-5 Hz. This can be mainly attributed to the removal of the lone-pair at pyrazole N-1 in the latter due to protonation or alkylation. According to the data obtained, 2-substituted 4-acyl-1,2-dihydro-3H-pyrazol-3- ones exist predominantly as pyrazol-5-ols in CDCl3 or benzene-d 6 solution, whereas in DMSO-d6 also minor amounts of NH tautomer may contribute to the tautomeric composition. 2,4-Dihydro-2-phenyl-3H- pyrazol-3-one (1-phenyl-2-pyrazolin-5-one) exists in benzene-d6 solely in the CH-form, in CDCl3 as a mixture of CH and OH-form, whereas in DMSO-d6 a fast equilibrium between OH and NH isomer (with the former far predominating) is probable. For 11 compounds, including neutral and protonated molecules, we have calculated at the B3LYP/6-311++G** level, the 2J(1H,13C) coupling constants which are in good agreement with those measured experimentally.