Cresol red
IUPAC: 4-[3-(4-hydroxy-3-methylphenyl)-1,1-dioxo-2,1lambda6-benzoxathiol-3-yl]-2-methylphenol
| Formula / Notation | C21H18O5S |
|---|---|
| CAS Number | 1733-12-6 |
| Molecular Weight | 382.4 |
| Appearance | Reddish-brown solid; [Merck Index] Reddish-brown or green odorless solid; [CHEMINFO] Crystalline solid; [MSDSonline] |
| Also Known As | 4-[3-(4-hydroxy-3-methylphenyl)-1,1-dioxo-2,1lambda6-benzoxathiol-3-yl]-2-methylphenol; 1733-12-6; o-Cresolsulfonphthalein; o-Cresol Red; Cresolsulfophthalein; o-Cresolsulfonephthalein; Phenol, 4,4'-(1,1-dioxido-3H-2,1-benzoxathiol-3-ylidene)bis[2-methyl-; 3',3''-Dimethylphenolsulfonephthalein; NSC 7224; 839K2R4B8K |
| Category | Indicators |
What is Cresol red?
Cresol red is a member of the class of 2,1-benzoxathioles that is 2,1-benzoxathiole 1,1-dioxide in which both of the hydrogens at position 3 have been substituted by 4-hydroxy-5-methylphenyl groups. It has a role as a dye, an acid-base indicator and a two-colour indicator. It is a polyphenol, a 2,1-benzoxathiole, a sultone and an arenesulfonate ester.
Formula & Notation
IUPAC Name: 4-[3-(4-hydroxy-3-methylphenyl)-1,1-dioxo-2,1lambda6-benzoxathiol-3-yl]-2-methylphenol
Other Names / Synonyms: 4-[3-(4-hydroxy-3-methylphenyl)-1,1-dioxo-2,1lambda6-benzoxathiol-3-yl]-2-methylphenol; 1733-12-6; o-Cresolsulfonphthalein; o-Cresol Red; Cresolsulfophthalein; o-Cresolsulfonephthalein; Phenol, 4,4'-(1,1-dioxido-3H-2,1-benzoxathiol-3-ylidene)bis[2-methyl-; 3',3''-Dimethylphenolsulfonephthalein; NSC 7224; 839K2R4B8K
Properties & Characteristics
Physical Data
| Property | Value |
|---|---|
| Molecular Weight | 382.4 |
| Appearance | Reddish-brown solid; [Merck Index] Reddish-brown or green odorless solid; [CHEMINFO] Crystalline solid; [MSDSonline] |
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
Cresol red is a member of the class of 2,1-benzoxathioles that is 2,1-benzoxathiole 1,1-dioxide in which both of the hydrogens at position 3 have been substituted by 4-hydroxy-5-methylphenyl groups. It has a role as a dye, an acid-base indicator and a two-colour indicator. It is a polyphenol, a 2,1-benzoxathiole, a sultone and an arenesulfonate ester.
Used as a pH indicator in acid-base titrations, analytical chemistry, and chemical education demonstrations.
May be irritant or toxic in concentrated form. Handle with care. Consult SDS before use.
The formula or notation for Cresol red is: C21H18O5S