Mchedlov-Petrossyan, Nikolay O. et al. published their research in Journal of Molecular Liquids in 2017 | CAS: 3326-34-9

5-Amino-3′,6′-dihydroxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one (cas: 3326-34-9) belongs to benzofurans derivatives. Benzofuran derivatives are one of the most important oxygen-containing heterocycles. Introduction of benzofurans in organic synthesis, particularly drug synthesis, involves generally the use of their metalated species as nucleophiles in addition reactions or in metal-catalysed cross-coupling reactions.Product Details of 3326-34-9

Acid-base dissociation and tautomerism of two aminofluorescein dyes in solution was written by Mchedlov-Petrossyan, Nikolay O.;Cheipesh, Tatyana A.;Vodolazkaya, Natalya A.. And the article was included in Journal of Molecular Liquids in 2017.Product Details of 3326-34-9 This article mentions the following:

The four-step dissociation of two fluorescein dyes bearing the amino group in 4′- and 5′-positions of the phthalic moiety was studied in water. The constants describing the equilibrium H4R2+⇌H3R+ ⇌ H2R ⇌ HR- ⇌ R2- were determined using the spectrophotometric method, at 25 °. In water, four steps of aminofluoresceins dissociation occur within pH range of 0-9. On going to 50 mass % aqueous ethanol, the increase in the pKa1, pKa2 and decrease in the pKa0, pKa(-1) values take place. The visible absorption spectra, referring to all the ionic (mol.) forms, were singled out. On the whole, the behavior of 4′-aminofluorescein is closer to that of the mother compound The shift of the equilibrium on introducing 50 mass % ethanol into the aqueous solution allowed better understanding the detailed scheme of prototropic equilibrium The tautomeric equilibrium of the mols. shifts toward the colorless lactone. This effect is expressed stronger for the 5′-aminofluorescein. For this dye, even signs of such tautomers of the single-charged anion as anion-lactone and phenolate anion are observed in aqueous ethanol, which are atypical for fluorescein in water-based solvents. In the experiment, the researchers used many compounds, for example, 5-Amino-3′,6′-dihydroxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one (cas: 3326-34-9Product Details of 3326-34-9).

5-Amino-3′,6′-dihydroxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one (cas: 3326-34-9) belongs to benzofurans derivatives. Benzofuran derivatives are one of the most important oxygen-containing heterocycles. Introduction of benzofurans in organic synthesis, particularly drug synthesis, involves generally the use of their metalated species as nucleophiles in addition reactions or in metal-catalysed cross-coupling reactions.Product Details of 3326-34-9

Referemce:
Benzofuran – Wikipedia,
Benzofuran | C8H6O – PubChem