Thymolphthalein

Thymolphthalein

Names
IUPAC name 3,3-bis(4-hydroxy-2-methyl-5-propan-2-ylphenyl)-2-benzofuran-1-one
Identifiers
CAS Number	125-20-2 N
3D model (Jmol)	Interactive image
ChEMBL	ChEMBL587849 Y
ChemSpider	29054 Y
ECHA InfoCard	100.004.300
EC Number	204-729-7
PubChem	31316
InChI InChI=1S/C28H30O4/c1-15(2)20-13-23(17(5)11-25(20)29)28(22-10-8-7-9-19(22)27(31)32-28)24-14-21(16(3)4)26(30)12-18(24)6/h7-16,29-30H,1-6H3 Y Key: LDKDGDIWEUUXSH-UHFFFAOYSA-N Y InChI=1/C28H30O4/c1-15(2)20-13-23(17(5)11-25(20)29)28(22-10-8-7-9-19(22)27(31)32-28)24-14-21(16(3)4)26(30)12-18(24)6/h7-16,29-30H,1-6H3 Key: LDKDGDIWEUUXSH-UHFFFAOYAV
SMILES O=C1OC(c2ccccc12)(c3cc(c(O)cc3C)C(C)C)c4cc(c(O)cc4C)C(C)C
Properties
Chemical formula	C28H30O4
Molar mass	430.54 g·mol−1
Appearance	White powder
Melting point	248 to 252 °C (478 to 486 °F; 521 to 525 K) (decomposes)
Hazards
R-phrases	4, 10
S-phrases	S22 S24/25
NFPA 704	0 1 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Thymolphthalein is an acid–base (pH) indicator. Its transition range is around pH 9.3–10.5. Below this pH, it is colorless; above, it is blue. The molar extinction coefficient for the blue thymolphthalein dianion is 38,000 M⁻¹ cm⁻¹ at 595 nm.

Thymolphthalein is also known to have use as a laxative.

Thymolphthalein can be synthesized from thymol and phthalic anhydride by Friedel–Crafts alkylation: