Dimethylformamide → HCID 59693001, compound

Temperature

80 °C

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.

1. concentrationThe obtained solution was concentrated
2. additionchloroform (100 mL) was added
3. customAfter azeotropic removal of residual solvent with chloroform, chloroform (50 mL)
4. additionwas added to the residue
5. extractionThe obtained mixture was extracted twice
6. washsequentially washed with water (20 mL) and saturated aqueous sodium chloride solution (10 mL)
7. dry with materialdried over magnesium sulfate
8. filtrationAfter filtration and evaporation
9. customthe obtained residue was separated
10. custompurified by silica gel chromatography (hexane:ethyl acetate=15:1)

ORD record

ord-026a686cfe0a4566ab661d253e090bca

Source dataset

uspto-grants-2008_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07351825B2