Dimethylformamide → HCID 59693001, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of 5-[5-(1,1-difluoroethyl)-isoxazol-3-yl]-thiophene-2-sulfonic acid (9.5 g, 32 mmol) obtained in Preparation Example 5-10-c) in thionyl chloride (50 mL) was added dimethylformamide (1.0 mL) under argon atmosphere, and the suspension was stirred at 80° C. for 16 hours. The obtained solution was concentrated, and chloroform (100 mL) was added. After azeotropic removal of residual solvent with chloroform, chloroform (50 mL) was added to the residue. The obtained mixture was extracted twice, sequentially washed with water (20 mL) and saturated aqueous sodium chloride solution (10 mL), and dried over magnesium sulfate. After filtration and evaporation, the obtained residue was separated and purified by silica gel chromatography (hexane:ethyl acetate=15:1) to give the title compound (6.9 g, 68%) as a yellow solid.

Provenance & Evidence