Weitz, Ernst et al. published their research in Zeitschrift fuer Elektrochemie und Angewandte Physikalische Chemie in 1940 | CAS: 36886-76-7

3′,6′-Dimethoxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one (cas: 36886-76-7) belongs to benzofurans derivatives. Benzofuran derivatives are one of the most important oxygen-containing heterocycles. They are also prone to polymerisation in the presence of concentrated mineral acids and Lewis acids.Safety of 3′,6′-Dimethoxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one

Polarization and color-change with the adsorption of surface-active substances. III was written by Weitz, Ernst;Schmidt, Fritz;Singer, Josef. And the article was included in Zeitschrift fuer Elektrochemie und Angewandte Physikalische Chemie in 1940.Safety of 3′,6′-Dimethoxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one This article mentions the following:

Ph3COMe is adsorbed with a yellow color by silica gel (I) or by acid-washed Al2O3 (II) from its colorless benzene solution, and decolorized by alc. [Me2NC6H4]3COMe is adsorbed from its colorless benzene solution by I and by Brockmann’s Al2O3 (III) with an intense blue-violet color. Ph3COCOMe is adsorbed by I with an intense brown-tinged yellow, by III with a pale yellow. Dimethylaniline phthalein (IV), colorless in benzene solution, gives an intense green-blue adsorbate on I, III, Al(OH)3, kaolin, AlPO4 and Ca3(PO4)2. If acetone vapors are poured over the blue adsorbate on kaolin, the color vanishes and returns when the vapor is dispersed. The colorless compound is malachite green lactone, the colored substance malachite green betaine. Powdered IV is adsorbed as the colored betaine by the adsorbents above, and the colored adsorbate is formed when the fused lactone is stirred with clay or kieselguhr, but not with KCl. The lactone form of rhodamine B is polarized to the colored (intensely red) form by all those substances that cause a similar transformation in IV, and in addition by CaCO3, MgO, paraformaldehyde and starch, from benzene solution, and also by rubbing with KCl, Na2SO4.10H2O, Na2CO3.10H2O, Na2S2O3.5H2O, paraformaldehyde, sugar or urea. Also tabulated is the color of the benzene solution, of the adsorbate on I, II and III, and the ease of elution with alc. for p-hydroxydiphenylphthalide, phenolphthalein, phenolphthalein di-Me ether, tetrabromophenolphthalein, fluorescein (in ether), fluorescein diacetate, fluorescein mono-Me ether, fluoroescein di-Me ether, benzylidene acetone, benzylideneacetophenone, cinnamylideneacetone, cinnamylideneacetophenone, anisylideneacetophenone and ω-nitrophenylethylene. The lactone-betaine tautomerism of thymol blue indicator is strikingly affected by temperature change. The unsaturated hydrocarbon 1,8-diphenyloctatetraene is adsorbed by I with a green color. In the experiment, the researchers used many compounds, for example, 3′,6′-Dimethoxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one (cas: 36886-76-7Safety of 3′,6′-Dimethoxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one).

3′,6′-Dimethoxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one (cas: 36886-76-7) belongs to benzofurans derivatives. Benzofuran derivatives are one of the most important oxygen-containing heterocycles. They are also prone to polymerisation in the presence of concentrated mineral acids and Lewis acids.Safety of 3′,6′-Dimethoxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one

Referemce:
Benzofuran – Wikipedia,
Benzofuran | C8H6O – PubChem