phthaleins

https://doi.org/10.1351/goldbook.P04662
3,3-Bis(hydroxyaryl)-2-benzofuran-1(3H)-ones generally derived from the condensation of phthalic anhydride with @P04539@. E.g. phenolphthalein.
P04662.png
See:
xanthene dyes
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1359 [Terms] [Paper]