1,2-二氢-5-甲基-2-苯基-3H-吡唑-3-酮

Description

1,2-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one · CAS 19735-89-8 · C10H10N2O. UNII S798V6YJRP. Boiling Point: 549 °F at 105 mmHg (NTP, 1992); Boiling Point: 287; Boiling Point: 191 °C @ 17 MM HG; 287 °C @ 105 MM HG.

Identification

CAS Registry Number	19735-89-8
PubChem CID	4021
Molecular formula	C10H10N2O
IUPAC name	5-methyl-2-phenyl-4H-pyrazol-3-one
UNII (FDA)	S798V6YJRP

Computed Descriptors

Molecular Weight	174.20
XLogP3	1.3
Hydrogen Bond Donor Count	0
Hydrogen Bond Acceptor Count	2
Rotatable Bond Count	1
Exact Mass	174.079312947
Monoisotopic Mass	174.079312947
Topological Polar Surface Area	32.7
Heavy Atom Count	13
Formal Charge	0

Physical & Chemical Properties

Boiling Point	549 °F at 105 mmHg (NTP, 1992)
Boiling Point	287
Boiling Point	191 °C @ 17 MM HG; 287 °C @ 105 MM HG
Melting Point	261 to 266 °F (NTP, 1992)
Melting Point	129.7
Melting Point	127 °C
Melting Point	128.9 °C
Vapor Pressure	LESS THAN 0.01 MM @ 20 °C
LogP	1.12
LogP	1.44

Physical description & handling notes

• 1-phenyl-3-methyl-5-pyrazolone appears as white to off-white powder or crystals. (NTP, 1992)
• White solid; [Merck Index] Light yellow odorless powder; [Alfa Aesar MSDS]
• MONOCLINIC PRISMS FROM WATER
• WHITE POWDER OR CRYSTALS
• less than 1 mg/mL at 73 °F (NTP, 1992)
• SOL IN HOT WATER & HOT ALCOHOL; SLIGHTLY SOL IN BENZENE; INSOL IN PETROLEUM ETHER

Regulatory Status

Regulatory & Food Contact	CIR / INCI: Cosmetic ingredients (Phenyl Methyl Pyrazolone) -> CIR (Cosmetic Ingredient Review) CIR / INCI: Hair dyeing
GHS notification summary	7.7% (16 / 209)

GHS Hazard Classification

GHS notification summary	7.7% (16 / 209)
Reported hazard statements	H302 (26.8%), H315 (34.4%), H317 (59.8%), H319 (23.4%), H335 (26.8%), H412 (52.2%)

Documented Uses

• CIR ingredient: Phenyl Methyl Pyrazolone
• Used as an intermediate for dyes and drugs, reagent to detect cyanide, and developer for diazotized direct dyes; [HSDB] Used in the treatment of strokes; [Merck Index] Used for synthesis in the chemical industry and in the textile processing industry; [IUCLID] Used in hair dyes; [ExPub: EC]
• Textiles (Printing, Dyeing, or Finishing) [Category: Industry]
• Dressing Hair [Category: Other]
• INTERMEDIATE FOR DYES & DRUGS; SENSITIVE REAGENT FOR DETECTION OF CYANIDE
• CHEM INT FOR DYES (EG, FOR PYRAZOLONE PIGMENTS), DRUGS (EG, ANTIPYRINE & AMINOPYRINE), DEVELOPER FOR DIAZOTISED DIRECT DYES, REAGENT FOR DETECTION OF CYANIDE

Synonyms

MCI-186; MCI 186; RefChem:57584; edaravone; 89-25-8; 3-METHYL-1-PHENYL-2-PYRAZOLIN-5-ONE; Radicut; Norphenazone; 1-Phenyl-3-methyl-5-pyrazolone; Developer Z; Methylphenylpyrazolone; Norantipyrine; C.I. Developer 1; Phenylmethylpyrazolone; Phenyl methyl pyrazolone; Radicava

Frequently Asked Questions

What are the CAS number and molecular formula of 1,2-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one?

CAS 19735-89-8; molecular formula C10H10N2O; molecular weight — g/mol.

What other names is 1,2-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one known by?

MCI-186, MCI 186, RefChem:57584, edaravone, 89-25-8, 3-METHYL-1-PHENYL-2-PYRAZOLIN-5-ONE.

What is the regulatory status of 1,2-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one?

Documented regulatory listings: CIR / INCI: Cosmetic ingredients (Phenyl Methyl Pyrazolone) -> CIR (Cosmetic Ingredient Review); CIR / INCI: Hair dyeing.

Is 1,2-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one classified as hazardous?

7.7% of GHS notifications report no hazard classification (16 of 209).

What are the key physical properties of 1,2-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one?

Boiling Point: 549 °F at 105 mmHg (NTP, 1992); Boiling Point: 287; Boiling Point: 191 °C @ 17 MM HG; 287 °C @ 105 MM HG; Melting Point: 261 to 266 °F (NTP, 1992).

Facts on this page are taken from PubChem (US National Library of Medicine) and Wikidata. Grade-specific data — assay, moisture, particle size, packaging, shelf life — is issued per batch on the COA and is not published here.