potassium;2-ethylhexanoate;hydrate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 422 mg (2.31 mmol) of potassium 2-ethylhexanoate hydrate was dissolved in 23 mL of ethyl acetate, and 1.215 g (2.31 mmol) of ethyl(2R,3R,8R)-8-[N-(2-bromo-4-fluorophenyl)sulfamoyl]-2,3-bis(hydroxymethyl)-1,4-dioxaspiro[4.5]deca-6-ene-7-carboxylate [a compound described as a low polarity compound (first peak) of Example 166 in WO 2007/032362] was added thereto under stirring at room temperature. The resulting reaction solution was concentrated under reduced pressure, and to the residue, diethyl ether was added. A precipitated solid was obtained by filtration and washed with diethyl ether, whereby 954 mg of a crude product was obtained as an amorphous solid. Then, the crude product was dissolved in 6 mL of ethyl acetate, and the resulting solution was heated under stirring at 70° C. for 5 minutes. After the resulting mixture was cooled, a precipitated solid was obtained by filtration and washed with ethyl acetate and diethyl ether, whereby 850 mg of the title compound was obtained as a white crystal (yield: 65%). was added The resulting reaction solution was concentrated under reduced pressure to the residue, diethyl ether was added A precipitated solid was obtained by filtration washed with diethyl ether whereby 954 mg of a crude product was obtained as an amorphous solid the resulting solution was heated under stirring at 70° C. for 5 minutes After the resulting mixture was cooled a precipitated solid was obtained by filtration washed with ethyl acetate and diethyl ether

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 100 mg (0.208 mmol) of ethyl (2R,3R,8R)-8-[N-(2-chloro-4-fluorophenyl)sulfamoyl]-2,3-bis(hydroxymethyl)-1,4-dioxaspiro[4.5]deca-6-ene-7-carboxylate [a compound described as a low polarity compound (first peak) of Example 162 in WO 2007/032362] was dissolved in 1 mL of ethyl acetate, and 2 mL of a solution containing 38 mg (0.208 mmol) of potassium 2-ethylhexanoate hydrate in ethyl acetate was added thereto under stirring at room temperature. The resulting reaction solution was concentrated under reduced pressure, and to the residue, diethyl ether was added. A precipitated solid was obtained by filtration and washed with diethyl ether, whereby 92 mg of a crude product was obtained as an amorphous solid. Then, the crude product was dissolved in ethyl acetate, and the resulting solution was heated under reflux at 130° C. for 2 hours. After the resulting mixture was cooled, a precipitated solid was obtained by filtration and washed with ethyl acetate, whereby the title compound was obtained as a white crystal. was added The resulting reaction solution was concentrated under reduced pressure to the residue, diethyl ether was added A precipitated solid was obtained by filtration washed with diethyl ether