6-amino-2,3,4-trichlorophenol

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

Procedure: 21.3 g of 2-amino-4,5,6-trichlorophenol, 27.6 g of anhydrous potassium carbonate and 150 ml of ethyl acetate were placed in a 300 ml round-bottom flask and a solution of 9.9 g of diphosgen (trichloromethyl chloroformate) dissolved in 50 ml of ethyl acetate was added dropwise to the mixture with stirring under cooling on ice-water bath. The resulting mixture was heated at reflux temperature for one hour and the reaction solution was then cooled and subjected to suction filtration to remove insoluble salts. The filtrate was concentrated to dryness under reduced pressure to afford yellowish white crystals, which were recrystallized from methanol/acetone to give 19.6 g of 5,6,7-trichlorobenzoxazolone as white crystals with a melting point of 253°-254° C. was added dropwise to the mixture under cooling on ice-water bath The resulting mixture was heated at reflux temperature for one hour the reaction solution was then cooled subjected to suction filtration to remove insoluble salts The filtrate was concentrated to dryness under reduced pressure to afford yellowish white crystals, which were recrystallized from methanol/acetone

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

Procedure: 21.3 g of 2-amino-4,5,6-trichlorophenol, 27.6 g of anhydrous potassium carbonate and 150 ml of ethyl acetate were placed in a 300 ml round-bottom flask and a solution of 9.9 g of diphosgen (trichloromethyl chloroformate) dissolved in 50 ml of ethyl acetate was added dropwise to the mixture with stirring under cooling on ice-water bath. The resulting mixture was heated at reflux temperature for one hour and the reaction solution was then cooled and subjected to suction filtration to remove insoluble salts. The filtrate was concentrated to dryness under reduced pressure to afford yellowish white crystals, which were recrystallized from methanol/acetone to give 19.6 g of 5,6,7-trichlorobenzoxazolone as white crystals with a melting point of 253°-254° C. was added dropwise to the mixture under cooling on ice-water bath The resulting mixture was heated at reflux temperature for one hour the reaction solution was then cooled subjected to suction filtration to remove insoluble salts The filtrate was concentrated to dryness under reduced pressure to afford yellowish white crystals, which were recrystallized from methanol/acetone

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

Procedure: 21.3 g of 2-amino-4,5,6-trichlorophenol, 27.6 g of anhydrous potassium carbonate and 150 ml of toluene were placed in a 300 ml round-bottom flask and 9.9 g of phosgen was slowly added to the mixture with stirring under cooling an ice-water bath. The resulting mixture was heated at reflux temperature for one hour and the reaction solution was then cooled and transferred to a 500 ml separating funnel. 150 ml of tetrahydrofuran and 150 ml of water were added into the funnel and the organic layer was separated, dried over anhydrous sodium sulfate and filtered. The filtrate was evaporated to remove the solvent, leaving yellowish white crystals. The crystals were recrystallized from a mixed solvent of methanol and acetone to give 22.7 g of 5,6,7-trichlorobenzoxazolone as white crystals having a melting point of 253°-254° C. under cooling an ice-water bath The resulting mixture was heated at reflux temperature for one hour the reaction solution was then cooled separating funnel 150 ml of tetrahydrofuran and 150 ml of water were added into the funnel the organic layer was separated dried over anhydrous sodium sulfate filtered The filtrate was evaporated to remove the solvent leaving yellowish white crystals The crystals were recrystallized from a mixed solvent of methanol and acetone

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

Procedure: 21.3 g of 2-amino-4,5,6-trichlorophenol, 27.6 g of anhydrous potassium carbonate and 150 ml of ethyl acetate were placed in a 300 ml round-bottom flask and a solution of 9.9 g of diphosgen (trichloromethyl chloroformate) dissolved in 50 ml of ethyl acetate was added dropwise to the mixture with stirring under cooling on ice-water bath. The resulting mixture was heated at reflux temperature for one hour and the reaction solution was then cooled and subjected to suction filtration to remove insoluble salts. The filtrate was concentrated to dryness under reduced pressure to afford yellowish white crystals, which were recrystallized from methanol/acetone to give 19.6 g of 5,6,7-trichlorobenzoxazolone as white crystals with a melting point of 253°-254° C. was added dropwise to the mixture under cooling on ice-water bath The resulting mixture was heated at reflux temperature for one hour the reaction solution was then cooled subjected to suction filtration to remove insoluble salts The filtrate was concentrated to dryness under reduced pressure to afford yellowish white crystals, which were recrystallized from methanol/acetone

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

Procedure: 21.3 g of 2-amino-4,5,6-trichlorophenol, 27.6 g of anhydrous potassium carbonate and 150 ml of toluene were placed in a 300 ml round-bottom flask and 9.9 g of phosgen was slowly added to the mixture with stirring under cooling an ice-water bath. The resulting mixture was heated at reflux temperature for one hour and the reaction solution was then cooled and transferred to a 500 ml separating funnel. 150 ml of tetrahydrofuran and 150 ml of water were added into the funnel and the organic layer was separated, dried over anhydrous sodium sulfate and filtered. The filtrate was evaporated to remove the solvent, leaving yellowish white crystals. The crystals were recrystallized from a mixed solvent of methanol and acetone to give 22.7 g of 5,6,7-trichlorobenzoxazolone as white crystals having a melting point of 253°-254° C. under cooling an ice-water bath The resulting mixture was heated at reflux temperature for one hour the reaction solution was then cooled separating funnel 150 ml of tetrahydrofuran and 150 ml of water were added into the funnel the organic layer was separated dried over anhydrous sodium sulfate filtered The filtrate was evaporated to remove the solvent leaving yellowish white crystals The crystals were recrystallized from a mixed solvent of methanol and acetone