To whom it may concern,
I am synthesizing some dyes according to this patent: "Sulfonated xanthene derivatives" Patent#: 6130101
There are some cleaning steps with Sephadex LH-20 in it e.g.
Preparation of Compound 1: ##STR25##
5-(and-6)-Carboxyrhodamine 110, hydrochloride (8.14 g, 19.8 mmol; Molecular Probes, Inc., Eugene, Oreg.) is slowly added in portions to 30% fuming H 2 SO 4 (50 mL) in an ice bath. After 12 hrs. at 0° C., the solution is poured into 600 mL cold dioxane, and 1.2 L Et 2 O is added. The suspension is filtered through diatomaceous earth. The filter cake is suspended in 1.2 L MeOH and the pH is adjusted to .about.10 with triethylamine. The mixture is filtered and the filtrate is evaporated. The residue is purified on SEPHADEX LH-20 using water as the eluant to give Compound 1 as an orange solid (9 g).
Is there a way to replace the Sephadex LH-20 with a cheaper media or a other method of cleaning?
Thank you for the help