Category
Heterocyclic Organic Compound
Description
Methyl red (2-(N,N-dimethyl-4-aminophenyl) azobenzenecarboxylic acid), also called C.I. Acid Red 2, is an indicator dye that turns red in acidic solutions. It is an azo dye, and is a dark red crystalline powder. Methyl red is a pH indicator; it is red in pH under 4.4, yellow in pH over 6.2, and orange in between, with a pKa of 5.1. Murexide and methyl red are investigated as promising enhancers of sonochemical destruction of chlorinated hydrocarbon pollutants. Methyl red is classed by the IARC in group 3 – unclassified as to carcinogenic potential in humans.
Synonyms
2-[4-(dimethylamino)phenylazo]benzoic acid;4′-dimethylaminoazobenzene-2-carboxylic acid;Methyl Red,indicator;2-(4-Dimethylaminophenylazo)benzoic acid;4-Dimethylaminoazobenzene-2′-carboxylic acid
IUPAC Name
2-[4-(dimethylamino)phenyl]diazenylbenzoic acid
Molecular Formula
C15H15N3O2
Canonical SMILES
CN(C)C1=CC=C(C=C1)N=NC2=CC=CC=C2C(=O)O
InChI Key
CEQFOVLGLXCDCX-UHFFFAOYSA-N
Boiling Point
479.5ºC at 760mmHg
Density
0.839 g/mL at 25ºC
Appearance
Red crystalline powder
Hazard Statements
Xn:Harmful;
Stability
Stable. Incompatible with strong oxidizing agents.
Vapor Pressure
2.89E-10mmHg at 25°C