2-amino-2-(4-fluorophenyl)acetamide

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Then, 30 g of concentrated sulfuric acid was added to 1.45 g of water, to which 20 g of 2-amino-2-(4-fluorophenyl)acetonitrile was added under ice cooling, and the mixture was heated at 50° to 60° C. under stirring for 3 hours. After completion of the reaction, the reaction mixture was poured into 200 ml of concentrated ammonia water cooled with ice in such a manner that the temperature of the solution became not higher than 20° C. The precipitated crystals were collected by filtration, and the filtrate was extracted with ethyl acetate. The organic layer was washed with saturated sodium chloride solution, dried with anhydrous magnesium sulfate, and concentrated. The residue was combined with the previously collected crystals, followed by recrystallization, which afforded 8.4 g (yield, 38%) of 2-amino-2-(4-fluorophenyl)acetamide. was added under ice cooling the mixture was heated at 50° to 60° C. After completion of the reaction cooled with ice in such a manner that the temperature of the solution became not higher than 20° C The precipitated crystals were collected by filtration the filtrate was extracted with ethyl acetate The organic layer was washed with saturated sodium chloride solution dried with anhydrous magnesium sulfate concentrated followed by recrystallization, which

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a mixed solution of 28 g of sodium carbonate and 100 ml of water was added dropwise 18.0 g of 1,1-dibromo-3,3,3-trifluoroacetone at such a rate that the temperature of the reaction mixture became not higher than 55° C. After completion of the dropwise addition, the mixture was stirred at room temperature for 30 minutes, followed by adding 125 ml of water and then 8.4 g of 2-amino-2-(4-fluorophenyl)acetamide, and the reaction was allowed to proceed at 60° C. for 2 hours. After completion of the reaction, the reaction mixture was cooled to 10° C. or lower, made acidic by adding 20 ml of concentrated hydrochloric acid at the same temperature, and extracted with ethyl acetate. The organic layer was washed with water and then saturated sodium chloride solution, dried with anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography (eluent, hexane/ethyl acetate=5:1), which afforded 2.45 g (yield, 19%) of the desired compound, 3-(4-fluorophenyl)-6-trifluoromethyl-2-oxo-1,2-dihydropyrazine (compound 1-1001). became not higher than 55° C After completion of the dropwise addition to proceed at 60° C. for 2 hours After completion of the reaction the reaction mixture was cooled to 10° C. extracted with ethyl acetate The organic layer was washed with water saturated sodium chloride solution, dried with anhydrous magnesium sulfate concentrated afforded

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Then, 30 g of concentrated sulfuric acid was added to 1.45 g of water, to which 20 g of 2-amino-2-(4-fluorophenyl)acetonitrile was added under ice cooling, and the mixture was heated at 50° to 60° C. under stirring for 3 hours. After completion of the reaction, the reaction mixture was poured into 200 ml of concentrated ammonia water cooled with ice in such a manner that the temperature of the solution became not higher than 20° C. The precipitated crystals were collected by filtration, and the filtrate was extracted with ethyl acetate. The organic layer was washed with saturated sodium chloride solution, dried with anhydrous magnesium sulfate, and concentrated. The residue was combined with the previously collected crystals, followed by recrystallization, which afforded 8.4 g (yield, 38%) of 2-amino-2-(4-fluorophenyl)acetamide. was added under ice cooling the mixture was heated at 50° to 60° C. After completion of the reaction cooled with ice in such a manner that the temperature of the solution became not higher than 20° C The precipitated crystals were collected by filtration the filtrate was extracted with ethyl acetate The organic layer was washed with saturated sodium chloride solution dried with anhydrous magnesium sulfate concentrated followed by recrystallization, which

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a mixed solution of 28 g of sodium carbonate and 100 ml of water was added dropwise 18.0 g of 1,1-dibromo-3,3,3-trifluoroacetone at such a rate that the temperature of the reaction mixture became not higher than 55° C. After completion of the dropwise addition, the mixture was stirred at room temperature for 30 minutes, followed by adding 125 ml of water and then 8.4 g of 2-amino-2-(4-fluorophenyl)acetamide, and the reaction was allowed to proceed at 60° C. for 2 hours. After completion of the reaction, the reaction mixture was cooled to 10° C. or lower, made acidic by adding 20 ml of concentrated hydrochloric acid at the same temperature, and extracted with ethyl acetate. The organic layer was washed with water and then saturated sodium chloride solution, dried with anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography (eluent, hexane/ethyl acetate=5:1), which afforded 2.45 g (yield, 19%) of the desired compound, 3-(4-fluorophenyl)-6-trifluoromethyl-2-oxo-1,2-dihydropyrazine (compound 1-1001). became not higher than 55° C After completion of the dropwise addition to proceed at 60° C. for 2 hours After completion of the reaction the reaction mixture was cooled to 10° C. extracted with ethyl acetate The organic layer was washed with water saturated sodium chloride solution, dried with anhydrous magnesium sulfate concentrated afforded