piperazine-2,6-dione

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

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

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

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

Procedure: A suspension of 0.098 mole of sodium hydride in 30 ml of anhydrous dimethylformamide is heated to 60° C. A solution of 0.098 mole of 4-(2-pyridylmethyl)-2,6-piperazinedione in 15 ml of anhydrous dimethylformamide is added dropwise. When the addition is complete, the mixture is maintained at 60° C. for two hours. The reaction medium is then cooled to 25° C. and a solution of 0.126 mole of 4-(4-fluorophenyl)-1-(3-chloropropyl)piperazine in 10 ml of anhydrous dimethylformamide and 0.1 g of sodium iodide are added rapidly. The mixture is heated to 70° C. until the starting 2,6-piperazinedione has completely disappeared. The reaction medium is concentrated under vacuum. The solid residue is recrystallized in a mixture of iospropyl ether and ethanol (90:10). Pure crystals of 4-(2-pyridylmethyl)-1-{3-[1-(4-fluorophenyl)-4-piperazinyl]propyl}-2,6-piperazinedione are obtained. When the addition the mixture is maintained at 60° C. for two hours The reaction medium is then cooled to 25° C. The reaction medium is concentrated under vacuum The solid residue is recrystallized in a mixture of iospropyl ether and ethanol (90:10)

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

Procedure: A suspension of 0.098 mole of sodium hydride in 30 ml of anhydrous dimethylformamide is heated to 60° C. A solution of 0.098 mole of 4-(2-pyridylmethyl)-2,6-piperazinedione in 15 ml of anhydrous dimethylformamide is added dropwise. When the addition is complete, the mixture is maintained at 60° C. for two hours. The reaction medium is then cooled to 25° C. and a solution of 0.126 mole of 4-(4-fluorophenyl)-1-(3-chloropropyl)piperazine in 10 ml of anhydrous dimethylformamide and 0.1 g of sodium iodide are added rapidly. The mixture is heated to 70° C. until the starting 2,6-piperazinedione has completely disappeared. The reaction medium is concentrated under vacuum. The solid residue is recrystallized in a mixture of iospropyl ether and ethanol (90:10). Pure crystals of 4-(2-pyridylmethyl)-1-{3-[1-(4-fluorophenyl)-4-piperazinyl]propyl}-2,6-piperazinedione are obtained. When the addition the mixture is maintained at 60° C. for two hours The reaction medium is then cooled to 25° C. The reaction medium is concentrated under vacuum The solid residue is recrystallized in a mixture of iospropyl ether and ethanol (90:10)

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a 25-mL round-bottom flask, was placed 4-[5-[3-chloro-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-(trifluoromethyl)benzoic acid (70 mg, 0.14 mmol, 1.00 equiv), N,N-dimethylformamide (3 mL), HATU (105 mg, 0.28 mmol, 2.00 equiv), DIEA (36 mg, 0.28 mmol, 1.96 equiv), piperazine-2,6-dione (32 mg, 0.28 mmol, 1.99 equiv). The resulting solution was stirred for 1 h at 25° C. The reaction was then quenched by the addition of 10 ml of water. The resulting solution was extracted with 2×10 mL of ethyl acetate and the organic layers combined. The resulting mixture was washed with 3×20 mL of brine. The resulting mixture was concentrated under vacuum. The residue was applied onto a TLC plate with ethyl acetate/petroleum ether (1/1). This resulted in 70 mg (76%) of 4-[(4-[5-[3-chloro-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-(trifluoromethyl)phenyl)carbonyl]piperazine-2,6-dione as colorless oil. Into a 25-mL round-bottom flask, was placed The reaction was then quenched by the addition of 10 ml of water The resulting solution was extracted with 2×10 mL of ethyl acetate The resulting mixture was washed with 3×20 mL of brine The resulting mixture was concentrated under vacuum This resulted in 70 mg (76%) of 4-[(4-[5-[3-chloro-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-(trifluoromethyl)phenyl)carbonyl]piperazine-2,6-dione as colorless oil

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a 50-mL round-bottom flask, was placed a solution of 4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-(trifluoromethyl)benzoic acid (300 mg, 0.64 mmol, 1.00 equiv) in N,N-dimethylformamide (2 mL), HATU (483 mg, 1.27 mmol, 2.00 equiv), DIEA (164 mg, 1.27 mmol, 2.00 equiv), piperazine-2,6-dione (145 mg, 1.27 mmol, 2.00 equiv). The resulting solution was stirred for 3 h at 20° C. The resulting solution was diluted with 50 mL of brine. The resulting solution was extracted with 3×50 mL of ethyl acetate and the organic layers combined. The mixture was dried over sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column with PE/EA (10:1). This resulted in 330 mg (91%) of 4-([4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-(trifluoromethyl)phenyl]carbonyl)piperazine-2,6-dione as a white solid. Into a 50-mL round-bottom flask, was placed The resulting solution was extracted with 3×50 mL of ethyl acetate The mixture was dried over sodium sulfate concentrated under vacuum This resulted in 330 mg (91%) of 4-([4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-(trifluoromethyl)phenyl]carbonyl)piperazine-2,6-dione as a white solid

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

Procedure: Into a 100-mL round-bottom flask, was placed 4-[5-[3-chloro-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-methylbenzoic acid (452 mg, 1.00 mmol, 1.00 equiv), dichloromethane (50 mL), TEA (202 mg, 2.00 mmol, 2.00 equiv), EDCI (384 mg, 2.00 mmol, 2.00 equiv), HOBt (270 mg, 2.00 mmol, 2.00 equiv). The mixture was stirred for 0.5 h at room temperature. This was followed by the addition of piperazine-2,6-dione (125 mg, 1.10 mmol, 1.10 equiv). The resulting solution was stirred overnight at room temperature. The resulting solution was diluted with 100 mL of DCM. The resulting mixture was washed with 3×50 mL of brine. The mixture was dried over anhydrous sodium sulfate. The resulting mixture was concentrated under vacuum. The residue was applied onto a silica gel column with ethyl acetate/petroleum ether (1:2). This resulted in 210 mg (38%) of 4-[(4-[5-[3-chloro-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-methylphenyl)carbonyl]piperazine-2,6-dione as a light yellow solid. Into a 100-mL round-bottom flask, was placed The resulting solution was stirred overnight at room temperature The resulting mixture was washed with 3×50 mL of brine The mixture was dried over anhydrous sodium sulfate The resulting mixture was concentrated under vacuum This resulted in 210 mg (38%) of 4-[(4-[5-[3-chloro-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-methylphenyl)carbonyl]piperazine-2,6-dione as a light yellow solid

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

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a 25-mL round-bottom flask, was placed 4-[5-[3-chloro-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-(trifluoromethyl)benzoic acid (70 mg, 0.14 mmol, 1.00 equiv), N,N-dimethylformamide (3 mL), HATU (105 mg, 0.28 mmol, 2.00 equiv), DIEA (36 mg, 0.28 mmol, 1.96 equiv), piperazine-2,6-dione (32 mg, 0.28 mmol, 1.99 equiv). The resulting solution was stirred for 1 h at 25° C. The reaction was then quenched by the addition of 10 ml of water. The resulting solution was extracted with 2×10 mL of ethyl acetate and the organic layers combined. The resulting mixture was washed with 3×20 mL of brine. The resulting mixture was concentrated under vacuum. The residue was applied onto a TLC plate with ethyl acetate/petroleum ether (1/1). This resulted in 70 mg (76%) of 4-[(4-[5-[3-chloro-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-(trifluoromethyl)phenyl)carbonyl]piperazine-2,6-dione as colorless oil. Into a 25-mL round-bottom flask, was placed The reaction was then quenched by the addition of 10 ml of water The resulting solution was extracted with 2×10 mL of ethyl acetate The resulting mixture was washed with 3×20 mL of brine The resulting mixture was concentrated under vacuum This resulted in 70 mg (76%) of 4-[(4-[5-[3-chloro-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-(trifluoromethyl)phenyl)carbonyl]piperazine-2,6-dione as colorless oil

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Into a 50-mL round-bottom flask, was placed a solution of 4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-(trifluoromethyl)benzoic acid (300 mg, 0.64 mmol, 1.00 equiv) in N,N-dimethylformamide (2 mL), HATU (483 mg, 1.27 mmol, 2.00 equiv), DIEA (164 mg, 1.27 mmol, 2.00 equiv), piperazine-2,6-dione (145 mg, 1.27 mmol, 2.00 equiv). The resulting solution was stirred for 3 h at 20° C. The resulting solution was diluted with 50 mL of brine. The resulting solution was extracted with 3×50 mL of ethyl acetate and the organic layers combined. The mixture was dried over sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column with PE/EA (10:1). This resulted in 330 mg (91%) of 4-([4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-(trifluoromethyl)phenyl]carbonyl)piperazine-2,6-dione as a white solid. Into a 50-mL round-bottom flask, was placed The resulting solution was extracted with 3×50 mL of ethyl acetate The mixture was dried over sodium sulfate concentrated under vacuum This resulted in 330 mg (91%) of 4-([4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-(trifluoromethyl)phenyl]carbonyl)piperazine-2,6-dione as a white solid

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

Procedure: Into a 100-mL round-bottom flask, was placed 4-[5-[3-chloro-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-methylbenzoic acid (452 mg, 1.00 mmol, 1.00 equiv), dichloromethane (50 mL), TEA (202 mg, 2.00 mmol, 2.00 equiv), EDCI (384 mg, 2.00 mmol, 2.00 equiv), HOBt (270 mg, 2.00 mmol, 2.00 equiv). The mixture was stirred for 0.5 h at room temperature. This was followed by the addition of piperazine-2,6-dione (125 mg, 1.10 mmol, 1.10 equiv). The resulting solution was stirred overnight at room temperature. The resulting solution was diluted with 100 mL of DCM. The resulting mixture was washed with 3×50 mL of brine. The mixture was dried over anhydrous sodium sulfate. The resulting mixture was concentrated under vacuum. The residue was applied onto a silica gel column with ethyl acetate/petroleum ether (1:2). This resulted in 210 mg (38%) of 4-[(4-[5-[3-chloro-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-methylphenyl)carbonyl]piperazine-2,6-dione as a light yellow solid. Into a 100-mL round-bottom flask, was placed The resulting solution was stirred overnight at room temperature The resulting mixture was washed with 3×50 mL of brine The mixture was dried over anhydrous sodium sulfate The resulting mixture was concentrated under vacuum This resulted in 210 mg (38%) of 4-[(4-[5-[3-chloro-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-2-methylphenyl)carbonyl]piperazine-2,6-dione as a light yellow solid