The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 26, 2020
Filed:
Feb. 27, 2019
Fudan University, Shanghai, CN;
Fener Chen, Shanghai, CN;
Lingdong Wang, Shanghai, CN;
Ge Meng, Shanghai, CN;
Zedu Huang, Shanghai, CN;
Dang Cheng, Shanghai, CN;
Haihui Peng, Shanghai, CN;
Guanfeng Liang, Shanghai, CN;
FUDAN UNIVERSITY, Shanghai, CN;
Abstract
The invention relates to the chemical synthesis of pharmaceutical API, and specifically to a method of synthesizing diclofenac sodium, which is a kind of nonsteroidal anti-inflammatory drug for relieving pain. The method includes: nitrating phenylacetate to prepare o-nitrophenylacetate (2); hydrogenating o-nitrophenylacetate (2) to prepare o-aminophenylacetate (3); amidating an amino group of o-aminophenylacetate (3) to obtain 2-(2-benzoylaminophenyl) acetate (4); 2-(2-benzoylaminophenyl) acetate (4) reacting with thionyl chloride to prepare a chloroimine intermediate, and then condensing the intermediate of chloroimine with 2,6-dichlorophenol using an inorganic base to prepare (E)-methyl-2-(2-((2,6-dichlorophenoxy)(phenyl)methyleneamino) phenyl ester (5); subjecting (E)-methyl-2-(2-((2,6-dichlorophenoxy)(phenyl)methyleneamino) phenyl ester (5) to Chapman rearrangement to afford methyl 2-(2-(N-(2,6-dichlorophenyl)benzoylamino)phenyl) ester (6); and hydrolyzing methyl 2-(2-(N-(2,6-dichlorophenyl)benzoylamino)phenyl) ester (6) to provide the target compound as of diclofenac sodium API. The overall yield is up to 67% based on methyl phenylacetate.