A method of synthesizing diclofenac sodium, including: subjecting aniline and chloroacetic acid to amidation to obtain 2-chloro-N-phenylacetamide; subjecting 2-chloro-N-phenylacetamide and 2,6-dichlorophenol to condensation reaction to obtain 2-(2,6-dichlorophenoxy)-N-phenylacetamide; subjecting 2-(2,6-dichlorophenoxy)-N-phenylacetamide to Smiles rearrangement in the presence of an inorganic base to obtain N-(2,6-dichlorophenyl)-2-hydroxy-N-phenylacetamide; subjecting N-(2,6-dichlorophenyl)-2-hydroxy-N-phenylacetamide and thionyl chloride to chlorination to obtain N-(2,6-dichlorophenyl)-2-chloro-N-phenylacetamide; subjecting N-(2,6-dichlorophenyl)-2-chloro-N-phenylacetamide to Friedel-Crafts alkylation in the presence of a Lewis acid catalyst to obtain 1-(2,6-dichlorophenyl)-1,3-dihydro-2H-indol-2-one; and subjecting 1-(2,6-dichlorophenyl)-1,3-dihydro-2H-indol-2-one to hydrolysis in the presence of an inorganic base to obtain diclofenac sodium.

A method of synthesizing diclofenac sodium, including: subjecting aniline and chloroacetic acid to amidation to obtain 2-chloro-N-phenylacetamide; subjecting 2-chloro-N-phenylacetamide and 2,6-dichlorophenol to condensation reaction to obtain 2-(2,6-dichlorophenoxy)-N-phenylacetamide; subjecting 2-(2,6-dichlorophenoxy)-N-phenylacetamide to Smiles rearrangement in the presence of an inorganic base to obtain N-(2,6-dichlorophenyl)-2-hydroxy-N-phenylacetamide; subjecting N-(2,6-dichlorophenyl)-2-hydroxy-N-phenylacetamide and thionyl chloride to chlorination to obtain N-(2,6-dichlorophenyl)-2-chloro-N-phenylacetamide; subjecting N-(2,6-dichlorophenyl)-2-chloro-N-phenylacetamide to Friedel-Crafts alkylation in the presence of a Lewis acid catalyst to obtain 1-(2,6-dichlorophenyl)-1,3-dihydro-2H-indol-2-one; and subjecting 1-(2,6-dichlorophenyl)-1,3-dihydro-2H-indol-2-one to hydrolysis in the presence of an inorganic base to obtain diclofenac sodium.

A method for synthesizing 5,8-diamino-3,4-dihydro-2H-1-naphthalenone (Compound I), which method comprises: subjecting 2,5-diprotected aminophenylbutyric acid to the Friedel-Crafts reaction for ring closure, and then removing a protecting group on the amino group to obtain Compound I.

A method for synthesizing 5,8-diamino-3,4-dihydro-2H-1-naphthalenone (Compound I), which method comprises: subjecting 2,5-diprotected aminophenylbutyric acid to the Friedel-Crafts reaction for ring closure, and then removing a protecting group on the amino group to obtain Compound I.

Different polymorphs of bromfenac sodium may be prepared and interconverted using crystallization/recrystallization, drying and/or hydration techniques.

Different polymorphs of bromfenac sodium may be prepared and interconverted using crystallization/recrystallization, drying and/or hydration techniques.

The present invention relates to a process for synthesis of 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol abbreviated THIP, having the INN name gaboxadol, starting from pyrrolidin-2-one. The process comprises a new direct process to obtain the intermediate dimethyl 5-hydroxy-3,6-dihydropyridine-1,4(2H)-5 dicarboxylate or the intermediate diethyl 5-hydroxy-3,6-dihydropyridine-1,4(2H)-dicarboxylate.

The present invention relates to a process for synthesis of 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol abbreviated THIP, having the INN name gaboxadol, starting from pyrrolidin-2-one. The process comprises a new direct process to obtain the intermediate dimethyl 5-hydroxy-3,6-dihydropyridine-1,4(2H)-5 dicarboxylate or the intermediate diethyl 5-hydroxy-3,6-dihydropyridine-1,4(2H)-dicarboxylate.

The present invention relates to a process for synthesis of 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol abbreviated THIP, having the INN name gaboxadol, starting from pyrrolidin-2-one. The process comprises a new direct process to obtain the intermediate dimethyl 5-hydroxy-3,6-dihydropyridine-1,4(2H)-5 dicarboxylate or the intermediate diethyl 5-hydroxy-3,6-dihydropyridine-1,4(2H)-dicarboxylate.

The present invention relates to a process for separating at least one -caprolactam oligomeric compound CPO from a stream S.sub.R comprising said at least one CPO and -caprolactam monomeric compound CPM.