Synthesis 2004(15): 2591-2593  
DOI: 10.1055/s-2004-829194
PSP
© Georg Thieme Verlag Stuttgart · New York

Preparation of 5- and 6-Carboxyfluorescein

Yuichiro Ueno, Guan-Sheng Jiao, Kevin Burgess*
Department of Chemistry, Texas A & M University, P.O. Box 30012, College Station, Texas 77842, USA
Fax: 001(979)8458839; e-Mail: burgess@tamu.edu;
Further Information

Publication History

Received 3 March 2004
Publication Date:
13 August 2004 (online)

Abstract

Condensation of resorcinol with 4-carboxyphthalic anhydride in methanesulfonic acid gave a mixture of 5- and 6-carboxyfluorescein stereoisomers. These were separated by recrystallization from methanol- or ethanol-hexane to give 5- and 6-carboxyfluorescein, each in over 98% purity.