Synthesis and Characterization of 2-(((2,7-Dihydroxynaphthalen-1-yl)methylene)amino)-3′,6′-bis(ethylamino)-2′,7′-dimethylspiro[isoindoline-1,9′-xanthen]-3-one and Colorimetric Detection of Uranium in Water

2-(((2,7-Dihydroxynaphthalen-1-yl)methylene)amino)-3′,6′-bis(ethylamino)-2′,7′-dimethyl-spiro[isoindoline-1,9′-xanthen]-3-one was synthesized using Rhodamine 6G hydrazide (prepared using literature methods) and commercially available 2,7-dihydroxynaphthalene-1-carbaldehyde via imine condensation. Structural characterization was performed using FT-IR, (1)H-NMR, (13)C-NMR, X-ray, and HRMS. This Schiff base shows promise as a ligand for the colorimetric analysis of uranium in water.