1-[4-(methylsulfonylmethyl)phenyl]ethanone

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

Procedure: N-Boc piperazine (485 mg, 2.61 mmol) was added to a stirred solution of a mixture of 1-(4-methanesulfonylmethyl-phenyl)-ethanone, 1-(4-chloromethyl-phenyl)-ethanone (obtained in STEP A, 580 mg) and TEA (0.522 ml, 3.75 mmol) in CH3CN (5 ml). The resulting mixture was stirred at room temperature overnight and then further TEA (0.250 ml, 1.80 mmol) and N-Boc piperazine (100 mg, 0.53 mmol) were added. After 4 h the solution was partitioned between water and AcOEt, the organic phase was dried over Na2SO4 and evaporated in vacuo. The crude mixture was purified by column chromatography (eluent: petroleum ether/AcOEt 7:3 to 6:4) to give 700 mg of 4-(4-acetyl-benzyl)-piperazine-1-carboxylic acid tert-butyl ester. After 4 h the solution was partitioned between water and AcOEt the organic phase was dried over Na2SO4 evaporated in vacuo The crude mixture was purified by column chromatography (eluent: petroleum ether/AcOEt 7:3 to 6:4)

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

Procedure: N-Boc piperazine (485 mg, 2.61 mmol) was added to a stirred solution of a mixture of 1-(4-methanesulfonylmethyl-phenyl)-ethanone, 1-(4-chloromethyl-phenyl)-ethanone (obtained in STEP A, 580 mg) and TEA (0.522 ml, 3.75 mmol) in CH3CN (5 ml). The resulting mixture was stirred at room temperature overnight and then further TEA (0.250 ml, 1.80 mmol) and N-Boc piperazine (100 mg, 0.53 mmol) were added. After 4 h the solution was partitioned between water and AcOEt, the organic phase was dried over Na2SO4 and evaporated in vacuo. The crude mixture was purified by column chromatography (eluent: petroleum ether/AcOEt 7:3 to 6:4) to give 700 mg of 4-(4-acetyl-benzyl)-piperazine-1-carboxylic acid tert-butyl ester. After 4 h the solution was partitioned between water and AcOEt the organic phase was dried over Na2SO4 evaporated in vacuo The crude mixture was purified by column chromatography (eluent: petroleum ether/AcOEt 7:3 to 6:4)

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

Procedure: N-Boc piperazine (485 mg, 2.61 mmol) was added to a stirred solution of a mixture of 1-(4-methanesulfonylmethyl-phenyl)-ethanone, 1-(4-chloromethyl-phenyl)-ethanone (obtained in STEP A, 580 mg) and TEA (0.522 ml, 3.75 mmol) in CH3CN (5 ml). The resulting mixture was stirred at room temperature overnight and then further TEA (0.250 ml, 1.80 mmol) and N-Boc piperazine (100 mg, 0.53 mmol) were added. After 4 h the solution was partitioned between water and AcOEt, the organic phase was dried over Na2SO4 and evaporated in vacuo. The crude mixture was purified by column chromatography (eluent: petroleum ether/AcOEt 7:3 to 6:4) to give 700 mg of 4-(4-acetyl-benzyl)-piperazine-1-carboxylic acid tert-butyl ester. After 4 h the solution was partitioned between water and AcOEt the organic phase was dried over Na2SO4 evaporated in vacuo The crude mixture was purified by column chromatography (eluent: petroleum ether/AcOEt 7:3 to 6:4)