2-(trifluoromethyl)piperazine

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:0.00; pressure:0.00; stir:

Conditions: temp:77.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 0.55 g portion of 2-(trifluoromethyl)piperazine was dissolved in 14 ml of pyridine. To this was added 265 mg of 1-cyclopropyl-6,7-difluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid. The mixture was stirred for 3 hours at 77° C.. The pyridine was removed by repeated evaporation with toluene. The residue was triturated with hot methanol. The resulting solid was collected, washed with methanol and ether and dried, giving 105 mg of the desired product as a colorless solid. The pyridine was removed evaporation with toluene The residue was triturated with hot methanol The resulting solid was collected washed with methanol and ether dried

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

Procedure: 2-Trifluoromethylpiperazine (Jenneskens et al., Ref. 31c) was prepared through a four step route (Scheme 6). Using Lewis acid TiCl4, N,N′-dibenzylethylenediamine 11 reacted with trifluoropyruvates 12 to afford hemiacetal 13, which was reduced at room temperature by Et3SiH in CF3COOH to lactam 14. LiAlH4 treatment then reduced lactam 14 to 1,4-dibenzyl-2-trifluoromethylpiperazine 15. Finally, hydrogenation of compound 15 in HOAc gave the desired product 2-trifluoromethylpiperazine 16.

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

Procedure: 2-Trifluoromethylpiperazine (Jenneskens et al., Ref. 88c) was prepared through a four step route (Scheme 56). Using Lewis acid TiCl4, N,N′-dibenzylethylenediamine reacted with trifluoropyruvates to afford the hemiacetal, which was reduced at room temperature by Et3SiH in TFA to afford the lactam. LiAlH4 treatment then reduced the lactam to 1,4-dibenzyl-2-trifluoromethylpiperazine. Finally, hydrogenation of the dibenzyl-2-trifluoromethylpiperazine in HOAc gave the desired product, 2-trifluoromethylpiperazine.

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

Procedure: 2-Trifluoromethylpiperazine (Jenneskens et al., Ref. 88c) was prepared through a four step route (Scheme 56). Using Lewis acid TiCl4, N,N′-dibenzylethylenediamine reacted with trifluoropyruvates to afford the hemiacetal, which was reduced at room temperature by Et3SiH in TFA to afford the lactam. LiAlH4 treatment then reduced the lactam to 1,4-dibenzyl-2-trifluoromethylpiperazine. Finally, hydrogenation of the dibenzyl-2-trifluoromethylpiperazine in HOAc gave the desired product, 2-trifluoromethylpiperazine.

Conditions: temp:77.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 0.55 g portion of 2-(trifluoromethyl)piperazine was dissolved in 14 ml of pyridine. To this was added 265 mg of 1-cyclopropyl-6,7-difluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid. The mixture was stirred for 3 hours at 77° C.. The pyridine was removed by repeated evaporation with toluene. The residue was triturated with hot methanol. The resulting solid was collected, washed with methanol and ether and dried, giving 105 mg of the desired product as a colorless solid. The pyridine was removed evaporation with toluene The residue was triturated with hot methanol The resulting solid was collected washed with methanol and ether dried

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

Procedure: A 12.3 g portion of bromo-3,3,3-trifluoropropanone was slowly added to 50 ml of dimethyl sulfoxide and stirred under a dry atmosphere for 21 hours and then diluted to 100 ml with ethanol. A solution of 31 g of N,N-dibenzylethylenediamine in 100 ml of ethanol was added dropwise and the mixture was stirred for 8 hours. A 2.43 g portion of sodium borohydride was added over 30 minutes, this mixture was stirred overnight then the ethanol was removed. The dimethyl sulfoxide residue was dissolved in water and extracted with dichloromethane. The extracts were combined, washed with water and brine and then subjected to flash chromatography on a silica gel column, eluting with ether:hexane (3:7). The 2-(trifluoromethyl)dibenzylpiperazine was dissolved in 25 ml of ethanol in an argon flushed Parr bottle. A 0.63 g portion of 10% palladium on carbon was added and the mixture was shaken under 47 lbs. of hydrogen pressure overnight at 40° C. Filtration and evaporation of the solvent gave 0.55 g of 2-(trifluoromethyl)piperazine as a semi-solid. the mixture was stirred for 8 hours this mixture was stirred overnight the ethanol was removed The dimethyl sulfoxide residue was dissolved in water extracted with dichloromethane washed with water and brine eluting with ether:hexane (3:7) The 2-(trifluoromethyl)dibenzylpiperazine was dissolved in 25 ml of ethanol in an argon flushed Parr bottle A 0.63 g portion of 10% palladium on carbon was added the mixture was shaken under 47 lbs of hydrogen pressure overnight at 40° C Filtration and evaporation of the solvent

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

Procedure: 1-Benzyl-3-(trifluoromethyl)piperazine 34a (4.1 mmol) is dissolved in MeOH (50 mL) followed by addition of AcOH (2.0 mL) and 5% mol of Pd/C. The flask is charged with a hydrogen balloon and stirred for 12 h. The mixture is filtered over celite and the filtrate is concentrated to afford 2-(trifluoromethyl)piperazine 35a, which is used without further purification. MS (m/z) (M+1)+: 155.1. The mixture is filtered over celite the filtrate is concentrated

Conditions: temp:140.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of (±)-2-(trifluoromethyl)piperazine (1 g, 6.2 mmol), 5-chloro-1-methyl-4-nitro-1H-pyrazole (2.1 g, 13 mmol), DIPEA (2.4 g, 18.6 mmol) in EtOH (10 mL) was heated in a microwave oven at 140° C. for 5 hours. The reaction mixture was concentrated under reduced pressure to give a residue. The residue was purified by silica gel chromatography using DCM/MeOH (10:1) as eluting solvents to afford (±)-1-(1-methyl-4-nitro-1H-pyrazol-5-yl)-3-(trifluoromethyl)piperazine as a yellow oil (1.8 g, 99%). MS (ESI) m/z: 280 [M+H+]. The reaction mixture was concentrated under reduced pressure to give a residue The residue was purified by silica gel chromatography as eluting solvents