O-Cresolphthalein

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o-Cresolphthalein

Names
Preferred IUPAC name 3,3-Bis(4-hydroxy-3-methylphenyl)-2-benzofuran-1(3H)-one
Identifiers
CAS Number	596-27-0
3D model (JSmol)	Interactive image
Beilstein Reference	5-18-04-00193
ChEMBL	ChEMBL1443546
ChemSpider	62217
ECHA InfoCard	100.008.985
EC Number	209-881-8
PubChem CID	68995
UNII	XOU2D9049G
CompTox Dashboard (EPA)	DTXSID9060491
InChI InChI=1S/C22H18O4/c1-13-11-15(7-9-19(13)23)22(16-8-10-20(24)14(2)12-16)18-6-4-3-5-17(18)21(25)26-22/h3-12,23-24H,1-2H3 Key: CPBJMKMKNCRKQB-UHFFFAOYSA-N
SMILES CC1=C(C=CC(=C1)C2(C3=CC=CC=C3C(=O)O2)C4=CC(=C(C=C4)O)C)O
Properties
Chemical formula	C22H18O4
Molar mass	346.382 g·mol−1
Appearance	White powder
Density	82.7 g/mL
Melting point	223 °C (433 °F; 496 K)
Boiling point	222.6 °C (432.68 °F; 495.75 K)
Solubility in water	Insoluble
Solubility	Soluble in ethanol
log P	1.975
Acidity (pKa)	9.61
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H312, H315, H319, H332, H335, H351
Precautionary statements	P201, P202, P261, P264, P270, P271, P280, P281, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P308+P313, P312, P321, P322, P330, P332+P313, P337+P313, P362, P363, P403+P233, P405, P501
Related compounds
Related compounds	Phenolphthalein Thymolphthalein
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

o-Cresolphthalein is a phthalein dye used as a pH indicator in titrations. It is insoluble in water but soluble in ethanol. Its solution is colourless below pH 8.2, and purple above 9.8. Its molecular formula is C₂₂H₁₈O₄. It is used medically to determine calcium levels in the human body, or to synthesize polyamides or polyimides.