Thymolphthalein

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Thymolphthalein
Thymolphthalein.svg
Names
Preferred IUPAC name
3,3-Bis[4-hydroxy-2-methyl-5-(propan-2-yl)phenyl]-2-benzofuran-1(3H)-one
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.004.300 Edit this at Wikidata
EC Number
  • 204-729-7
UNII
  • 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 checkY
    Key: LDKDGDIWEUUXSH-UHFFFAOYSA-N checkY
  • 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
  • O=C1OC(c2ccccc12)(c3cc(c(O)cc3C)C(C)C)c4cc(c(O)cc4C)C(C)C
Properties
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
R-phrases (outdated) 4, 10
S-phrases (outdated) S22 S24/25
NFPA 704 (fire diamond)
1
0
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 checkY☒N ?)
Infobox references

Thymolphthalein is a phthalein dye used as an acidbase (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.[1]

Thymolphthalein (pH indicator)
below pH 9.3 above pH 10.5
9.3 10.5
Thymolphthalein (pH indicator)
below pH <0 above pH 9.3
<0 9.3

Thymolphthalein is also known to have use as a laxative[2] and for disappearing ink.[3]

Preparation[edit]

Thymolphthalein can be synthesized from thymol and phthalic anhydride

ThymolphthaleinSynthesis.png

References[edit]

  1. ^ Hahn HH; Cheuk SF; Elfenbein S; Wood WB (April 1970). "Studies on the Pathogenesis of Fever: Xix. Localization of Pyrogen in Granulocytes". J. Exp. Med. 131 (4): 701–9. doi:10.1084/jem.131.4.701. PMC 2138774. PMID 5430784.
  2. ^ Hubacher, MH; Doernberg, S; Horner, A (1953). "Laxatives: chemical structure and potency of phthaleins and hydroxyanthraquinones". J Am Pharm Assoc Am Pharm Assoc. 42 (1): 23–30. doi:10.1002/jps.3030420108. PMID 13034620.
  3. ^ Katz, David A. (1982). "Disappearing Ink" (PDF). www.chymist.com. Retrieved August 14, 2017.