Diclofenac → S-Diclofenac

Temperature

0 °C

To the solution of 1 (diclofenac, 890 mg, 3.0 mmol) in 50 mL of N,N-dimethylformamide, hydroxybenzotriazole (445 mg, 3.3 mmol) and DCC (680 mg, 3.3 mmol) were added with stirring at 0° C. for 1 h. To the reaction mixture 5-p-hydroxyphenyl-1,2-dithiole-3-thione (2; 678 mg, 3 mmol) was added and stirred for 1 h at 0° C. and 3 h at room temperature. After filtration, the filtrate was evaporated under reduced pressure and the oily residue thus obtained was dissolved in ethyl acetate; the organic layer was washed with brine, dried on anhydrous MgSO4, filtered and the solvent evaporated. The crude product 3 was loaded on a silica gel open column and eluted with CH2Cl2/MeOH (9/1), from which [2-(2,6-dichloro-phenylamino)-phenyl]-acetic acid 4-(5-thioxo-5H-[1,2]dithiol-3-yl)-phenyl ester (3) was obtained (1.1 g, 74% yield).

1. stirringstirred for 1 h at 0° C. and 3 h at room temperature
2. filtrationAfter filtration
3. customthe filtrate was evaporated under reduced pressure
4. customthe oily residue thus obtained
5. washthe organic layer was washed with brine
6. dry with materialdried on anhydrous MgSO4
7. filtrationfiltered
8. customthe solvent evaporated
9. washeluted with CH2Cl2/MeOH (9/1), from which [2-(2,6-dichloro-phenylamino)-phenyl]-acetic acid 4-(5-thioxo-5H-[1,2]dithiol-3-yl)-phenyl ester (3)
10. customwas obtained (1.1 g, 74% yield)

ORD record

ord-524b1f6b99df4db48a59db8265a7f4eb

Source dataset

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08541398B2