Potassium Carbonate → (5-Chloro-2-{2-[4-(4-fluoro-benzyl)-(2R,5S)-2,5-dimethyl-piperazin-1-yl]-2-oxo-ethoxy}-phenylsulfamoyl)-acetic Acid

Participants

Reaction Steps

To a solution of 2-(2-amino-4-chloro-phenoxy)-1-[4-(4-fluoro-benzyl)-(2R,5S)-2,5-dimethyl-piperazin-1-yl]-ethanone (0.030 g, 0.074 mmol) in dimethylformamide (0.5 ml) was added potassium carbonate (0.030 g, 0.239 mmol), chlorosulfonyl-acetic acid ethyl ester (0.02 g, 0.12 mmol) (for preparation, see: Helv. Chim. Acta., (1997) 80, 671 and Bull. Soc. Chim. Fr. (1975), 807) in dimethylformamide (0.5 ml) and finally catalytic dimethylaminopyridine. After 23 hours the reaction was diluted with ethyl acetate and washed with pH 7.0 phosphate buffer (0.05 M). The organic layer was dried over magnesium sulfate, filtered and concentrated. The crude ester was then dissolved in 1:1 tetrahydrofuran:water (0.5 ml) and lithium hydroxide hydrate (0.004 g, 0.095 mmol) was added. After 19 hours the reaction was concentrated and the title compound purified by silica gel chromatography (0.006 g, LRMS: 528.3).

Provenance & Evidence