5-Hydroxy-1-methylpyrazole
[CAS# 33641-15-5]

Identification

• Name: 5-Hydroxy-1-methylpyrazole
• Synonyms: 1-Methyl-1H-pyrazol-5-ol; 1-Methyl-5-hydroxy-1H-pyrazole; 1-Methyl-5-hydroxypyrazole; 2-Methyl-2H-pyrazol-3-ol; 5-Hydroxy-1-methyl-5-pyrazole
• Molecular Formula: C₄H₆N₂O
• Molecular Weight: 98.10
• CAS Registry Number: 33641-15-5
• EC Number: 608-897-6

Properties

• Solubility: Sparingly soluble (25 g/L) (25 ºC), Calc.^*
• Density: 1.22±0.1 g/cm³ (20 ºC 760 Torr), Calc.^*
• Melting point: 70-110 ºC (benzene )^**
• Boiling point: 217.7±13.0 ºC (760 Torr), Calc.^*
• Flash point: 85.4±19.8 ºC, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software V11.02 (©1994-2013 ACD/Labs)

^** Sucrow, Wolfgang; Chemische Berichte 1976, V109(1), P261-7.

Safety Data

• Hazard Symbols: Xn
• Risk Codes: R22;R37/38;R41
• Safety Description: S26;S39

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Serious eye damage	Eye Dam.	1	H318
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319