methyl 2,5-difluorobenzoate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Thus, 2-aminobenzenethiol may be reacted with 2,5-difluoro-benzoic acid methyl ester to form a 2-[(E)-2-amino-1-eth-(E)-ylidene-but-2-enylsulfanyl]-5-fluoro-benzoic acid methyl ester intermediate that can be converted by treatment with alkali to 2-[(E)-2-amino-1-eth-(E)-ylidene-but-2-enylsulfanyl]-5-fluoro-benzoic acid. The benzoic acid can be cyclized to form 2-fluoro-10H-dibenzo[b,f][1,4]thiazepin-11-one, that may be converted to 11-chloro-2-fluoro-dibenzo[b,f][1,4]thiazepine, that may be further reacted with piperazine to form the title compound.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Thus, 2-aminobenzenethiol may be reacted with 2,5-difluoro-benzoic acid methyl ester to form a 2-[(E)-2-amino-1-eth-(E)-ylidene-but-2-enylsulfanyl]-5-fluoro-benzoic acid methyl ester intermediate that can be converted by treatment with alkali to 2-[(E)-2-amino-1-eth-(E)-ylidene-but-2-enylsulfanyl]-5-fluoro-benzoic acid. The benzoic acid can be cyclized to form 2-fluoro-10H-dibenzo[b,f][1,4]thiazepin-11-one, that may be converted to 11-chloro-2-fluoro-dibenzo[b,f][1,4]thiazepine, that may be further reacted with piperazine to form the title compound.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Thus, 2-aminobenzenethiol may be reacted with 2,5-difluoro-benzoic acid methyl ester to form a 2-[(E)-2-amino-1-eth-(E)-ylidene-but-2-enylsulfanyl]-5-fluoro-benzoic acid methyl ester intermediate that can be converted by treatment with alkali to 2-[(E)-2-amino-1-eth-(E)-ylidene-but-2-enylsulfanyl]-5-fluoro-benzoic acid. The benzoic acid can be cyclized to form 2-fluoro-10H-dibenzo[b,f][1,4]thiazepin-11-one, that may be converted to 11-chloro-2-fluoro-dibenzo[b,f][1,4]thiazepine, that may be further reacted with piperazine to form the title compound.

Conditions: temp:110.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2,5-Difluorobenzoic acid methyl ester (25 g, 145 mmol), piperazine-1-carboxylic acid tert-butyl ester (27 g, 145 mmol) and K2CO3 (50 g, 363 mmol) are added to 1,4-dioxane and the mixture is heated to 110° C. for 2 days. The reaction mixture is cooled, inorganic salts filtered through sintered funnel and filtrate is concentrated under reduced pressure. Crude compound is purified by column chromatography (silica-gel, 100-200 mesh, eluent; 5% EtOAc in hexane) to afford desired 4-(4-fluoro-2-methoxycarbonyl-phenyl)-piperazine-1-carboxylic acid tert-butyl ester as a syrupy liquid (8.1 g, 16.3%). The reaction mixture is cooled inorganic salts filtered through sintered funnel filtrate is concentrated under reduced pressure Crude compound is purified by column chromatography (silica-gel, 100-200 mesh, eluent; 5% EtOAc in hexane)

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 2,5-difluorobenzoic acid (20 g, 126 mmol) in MeOH (250 mL) is added thionyl chloride (22.5 g, 190 mmol) dropwise at ice-cold conditions. After complete addition the reaction mixture is heated at 60° C. for 3 h. The reaction mixture is concentrated and the residue neutralized with aqueous Na2CO3 solution. It is extracted with CH2Cl2 (3×100 mL), dried over anhydrous MgSO4 and concentrated under reduced pressure to afford the desired 2,5-difluorobenzoic acid methyl ester as a thick liquid (22 g). After complete addition the reaction mixture The reaction mixture is concentrated It is extracted with CH2Cl2 (3×100 mL) dried over anhydrous MgSO4 concentrated under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Thus, 2-aminobenzenethiol may be reacted with 2,5-difluoro-benzoic acid methyl ester to form a 2-[(E)-2-amino-1-eth-(E)-ylidene-but-2-enylsulfanyl]-5-fluoro-benzoic acid methyl ester intermediate that can be converted by treatment with alkali to 2-[(E)-2-amino-1-eth-(E)-ylidene-but-2-enylsulfanyl]-5-fluoro-benzoic acid. The benzoic acid can be cyclized to form 2-fluoro-10H-dibenzo[b,f][1,4]thiazepin-11-one, that may be converted to 11-chloro-2-fluoro-dibenzo[b,f][1,4]thiazepine, that may be further reacted with piperazine to form the title compound.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Thus, 2-aminobenzenethiol may be reacted with 2,5-difluoro-benzoic acid methyl ester to form a 2-[(E)-2-amino-1-eth-(E)-ylidene-but-2-enylsulfanyl]-5-fluoro-benzoic acid methyl ester intermediate that can be converted by treatment with alkali to 2-[(E)-2-amino-1-eth-(E)-ylidene-but-2-enylsulfanyl]-5-fluoro-benzoic acid. The benzoic acid can be cyclized to form 2-fluoro-10H-dibenzo[b,f][1,4]thiazepin-11-one, that may be converted to 11-chloro-2-fluoro-dibenzo[b,f][1,4]thiazepine, that may be further reacted with piperazine to form the title compound.