Hydrochloric Acid → 6-Fluoro-3-[(E)-2-(thiophen-2-yl)-vinyl]-1H-indazole-5-carboxylic Acid

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Reaction Steps

To a mixed solution of 60 mg of 6-fluoro-3-[(E)-2-(thiophen-2-yl)-vinyl]-1H-indazole-5-carboxylic acid methyl ester obtained by Example 142 in a mixture of 2 mL tetrahydrofuran/0.5 mL methanol was added 0.5 mL of 5N sodium hydroxide aqueous solution, and stirred at 50° C.-55° C. for 6 hours. The reaction solution was made acidic with 1N hydrochloric acid, and extracted with 15 mL of ethyl acetate. The organic layer was washed successively with water and saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated, to afford 53 mg of the title compound as bright yellow crystals.

Provenance & Evidence