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also phthal·eine  (thăl′ēn′, thăl′ē-ĭn, thā′lēn′, thā′lē-ĭn, fthăl′-)
Any of a group of chemical compounds formed by a reaction of phthalic anhydride with a phenol, from which certain synthetic dyes are derived.

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(ˈθeɪliːn; -lɪɪn; ˈθæl-; ˈfθæl-)
(Elements & Compounds) any of a class of organic compounds obtained by the reaction of phthalic anhydride with a phenol and used in dyes
[C19: from phthal-, shortened form of naphthalene +-in]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈθæl in, -i ɪn, ˈfθæl-)

any of a group of compounds formed by treating phthalic anhydride with phenols, from which certain important dyes are derived.
[1900–05; (na) phthale (ne) + -in1]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
References in periodicals archive ?
This was due to the hydrolysis of ethyl phthalein on wood hemicellulose to form acetic acid.
These include: PB1 (triarylcarbonium), PB52 (anthraquinone), PB63 (indigo, sulfonic acid), PR90:1 (phthalein), PR169 (triarylcarbonium), PR172 (tetraiodofluoresceine), PR174 (phthalein), PV1 (triarylcarbonium), PV3 (triarylcarbonium), PV3:1 (triarylcarbonium), PV5 (triarylcarbonium), PV27 (triarylcarbonium), PY100 (monoazopyrazolone), and PY104 (naphthalene sulfonic acid, Al salt).