Continuous-flow preparation method of diclofenac sodium
US11834388B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 2023 |
| Grant date | Dec 5, 2023 |
| Priority date | — |
| Expiry date | Feb 22, 2043 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C231/12
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
This application relates to pharmaceutical engineering, and more particularly to a continuous-flow preparation method of diclofenac sodium. The continuous-flow preparation method includes: subjecting aniline and chloroacetic acid to amidation to obtain 2-chloro-N-phenylacetamide (3); subjecting 2-chloro-N-phenylacetamide (3) and 2,6-dichlorophenol to continuous condensation to obtain N-(2,6-dichlorophenyl)-2-hydroxy-N-phenylacetamide (5); subjecting N-(2,6-dichlorophenyl)-2-hydroxy-N-phenylacetamide (5) and thionyl chloride to chlorination to obtain N-(2,6-dichlorophenyl)-2-chloro-N-phenylacetamide (6); subjecting N-(2,6-dichlorophenyl)-2-chloro-N-phenylacetamide (6) to Friedel-Crafts alkylation in the presence of aluminum chloride to obtain 1-(2,6-dichlorophenyl)-1,3-dihydro-2H-indol-2-one (7); and subjecting 1-(2,6-dichlorophenyl)-1,3-dihydro-2H-indol-2-one (7) to hydrolysis to obtain the diclofenac sodium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.