phthalides

https://doi.org/10.1351/goldbook.P04663

3,3-Di(hydrocarbyl) or 3-hydrocarbylidene-2-benzofuran-1(3H)-ones.

See: phthaleins

Source:
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1359 (https://doi.org/10.1351/pac199567081307)