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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 1824450Generated: November 2, 2026

Phthalic Anhydride → 4',5'-Dimethylfluorescein

https://huagongshe.com/reaction/1824450

Reaction equation

Participants

RoleNameHCIDCharge
ReactantPhthalic AnhydrideHCID 6811—
Reactant2-MethylresorcinolHCID 11843—
CatalystZincchlorideHCID 3007855—
SolventHydrochloric AcidHCID 313—
Product4',5'-DimethylfluoresceinHCID 3082937—

Reaction Conditions

Temperature230 °C

Reaction Steps

In a round bottom flask, phthalic anhydride (16.7 g, 113 mmol) and 2-methylresorcinol (24.9 g, 201 mmol) were combined and melted into a brown liquid at 150° C. Fused ZnCl2 (15 g, 110 mmol) was added over 40 min, and the temperature was slowly increased to 230° C. until all material solidified. The brick red solid was pulverized and boiled in 6M HCl for 30 min. The red solid was collected on a glass frit, washed with water, and dried in air over night (yield: 32.62 g, 91% of the theoretical yield).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS07041821B2
Source datasetuspto-grants-2006_05
ORD IDord-4f8d2e8179ab4e8d9acd819fa574abb6
Source noteuspto-grants-2006_05