Chemistry:Thymolphthalein

Thymolphthalein

Names
Preferred IUPAC name 3,3-Bis[4-hydroxy-2-methyl-5-(propan-2-yl)phenyl]-2-benzofuran-1(3H)-one
Identifiers
CAS Number	125-20-2 Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL587849 Y
ChemSpider	29054 Y
EC Number	204-729-7
PubChem CID	31316
UNII	YG5I28WSQP Y
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	430.544 g·mol−1
Appearance	White powder
Melting point	248 to 252 °C (478 to 486 °F; 521 to 525 K) (decomposes)
Hazards
GHS pictograms
GHS Signal word	Warning
GHS hazard statements	H341, H350, H361
GHS precautionary statements	P201, P202, P210, P233, P240, P241, P242, P243, P280, P281, P303+361+353, P308+313, P370+378, P403+235, P405, P501
NFPA 704 (fire diamond)	0 1 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Thymolphthalein is a phthalein dye used as 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 (pH indicator)
below pH 9.3		above pH 10.5
9.3	⇌	10.5

Thymolphthalein is also known to have use as a laxative and for disappearing ink.

Preparation

Thymolphthalein can be synthesized from thymol and phthalic anhydride.

See also

• Phenolphthalein