Three Novel Seminaphthorhodamines: Synthesis, Structure, and Spectral Properties

Altering Fundamental Trends in the Emission of Xanthene Dyes

“…Subsequent Fischer esterification to produce the methyl ester derivatives was carried out under reflux conditions in anhydrous MeOH and catalyzed by HCl. The required starting materials 2-(2,4-dihydroxybenzoyl)­benzoic acid, 2-(4-amino-2-hydroxybenzoyl)­benzoic acid, 2-(8-hydroxy-1,2,3,5,6,7-hexahydropyrido­[3,2,1- i j ]­quinoline-9-carbonyl)­benzoic acid, and 2,7-naphthalene derivatives were synthesized according to published literature protocols. ,, In the case of the seminaphthorhodamines (Figure ), we followed a protocol developed recently by our group . All compounds were isolated by flash column chromatography on silica gel, preparative TLC, or medium-pressure reversed phase chromatography and characterized by 1D and 2D NMR as well as HR-ESI-MS.…”

“…10,16,17 In the case of the seminaphthorhodamines (Figure 2), we followed a protocol developed recently by our group. 18 All compounds were isolated by flash column chromatography on silica gel, preparative TLC, or medium-pressure reversed phase chromatography and characterized by 1D and 2D NMR as well as HR-ESI-MS. Detailed characterization data and procedures are described in the Experimental Section.…”