Marquez, Luis Alberto Ponce published the artcileSynthesis and chemical study of some phenolic phthaleins and their halogenated derivatives, Product Details of C28H18O4, the publication is Anales de la Facultad de Farmacia y Bioquimica, Universidad Nacional Mayor de San Marcos (1950-57) (1956), 581-8, database is CAplus.
Various phenols were treated with ο-C6H4(CO)2O to form the corresponding phthaleins (I) which were halogenated to halophthaleins (II). During the formation of I, the temperature must be maintained below 120° to avoid carbonization or volatilization of the reactants. The halogenation must be conducted in the cold under mildly alk. conditions to obtain good yields of II. Iodinated phthaleins lactonize readily.
Anales de la Facultad de Farmacia y Bioquimica, Universidad Nacional Mayor de San Marcos (1950-57) published new progress about 596-01-0. 596-01-0 belongs to benzofurans, auxiliary class Benzofuran,Naphthalene,Alcohol,Ester, name is 3,3-Bis(4-hydroxynaphthalen-1-yl)isobenzofuran-1(3H)-one, and the molecular formula is C28H18O4, Product Details of C28H18O4.
Referemce:
https://en.wikipedia.org/wiki/Benzofuran,
Benzofuran | C8H6O – PubChem