4-(2-Pyridinylazo)resorcinol
[CAS# 1141-59-9]

Identification

• Classification: Biochemical >> Biochemical reagent >> Acid-base indicator
• Name: 4-(2-Pyridinylazo)resorcinol
• Synonyms: 4-(2-Pyridylazo)-1,3-benzenediol; 4-(2-Pyridylazo)resorcinol; NSC 148355; PAR; PAR (resorcinol derivative)
• Molecular Formula: C₁₁H₉N₃O₂
• Molecular Weight: 215.21
• CAS Registry Number: 1141-59-9
• EC Number: 214-528-6

Properties

• Solubility: Slightly soluble (1.4 g/L) (25 ºC), Calc.^*
• Density: 1.33±0.1 g/cm³ (20 ºC 760 Torr), Calc.^*
• Melting point: 196-198 ºC^**

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software V11.02 (©1994-2014 ACD/Labs)

^** Wiejak, Stanislaw; Polish Journal of Chemistry 1984, V58(7-9), P895-7.

Safety Data

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	3	H301
Acute toxicity	Acute Tox.	3	H331
Acute toxicity	Acute Tox.	3	H311