3-Methyl-1-phenylpyrazolone

  • 1-Phenyl-3-methyl-2-prazolin-5-one
  • 3-Methyl-1-phenylpyrazolin-5(4H)-one
  • 1,2-Dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one
Formula
C10H10N2O
Structure
Description
White to off-white crystals or powder.

Registry Numbers and Inventories.
CAS
19735-89-8
EC (EINECS/ELINCS)
243-261-8
Beilstein/Gmelin
140723
Beilstein Reference
4-24-00-00071
Japan ENCS (MITI)
Listed

Properties.
Formula
C10H10N2O
Formula mass
174.20
Melting point, °C
127 - 128
Boiling point, °C
276
Vapor pressure, mmHg
0.005 (25 C)
Density
1.26 g/cm3 (20 C)
Solubility in water
Slightly soluble
Refractive index
1.637
pKa/pKb
13.21 (pKb)
Heat of vaporization
51.5 kJ/mol

Hazards and Protection.
Storage
Store in an explosion proof refrigerator.
Respirators
Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter.
Small spills/leaks
Should a spill occur while you are handling this chemical, FIRST REMOVE ALL SOURCES OF IGNITION, then you should dampen the solid spill material with ethanol and transfer the dampened material to a suitable container. Use absorbent paper dampened with ethanol to pick up any remaining material. Seal the absorbent paper, and any of your clothes, which may be contaminated, in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with ethanol followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

Fire.
Flash Point,°C
121
Fire fighting
Fires involving this material can be controlled with a dry chemical, carbon dioxide or Halon extinguisher.

Health.
Exposure effects
   Ingestion
Moderately toxic.
   Inhalation
Causes irritation.
   Skin
Causes irritation.
   Eyes
Causes irritation.

First aid
 
   Ingestion
DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital.
   Inhalation
IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.
   Skin
IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.
   Eyes
First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

Transport.