Methanesulfonyl chloride → Tert-butyl 4-(2-(methylsulfonamido)ethyl)piperazine-1-carboxylate
Reaction equation
[CH3:1][S:2](Cl)(=[O:4])=[O:3].[C:6]([O:10][C:11]([N:13]1[CH2:18][CH2:17][N:16]([CH2:19][CH2:20][NH2:21])[CH2:15][CH2:14]1)=[O:12])([CH3:9])([CH3:8])[CH3:7]>N1C=CC=CC=1>[C:6]([O:10][C:11]([N:13]1[CH2:14][CH2:15][N:16]([CH2:19][CH2:20][NH:21][S:2]([CH3:1])(=[O:4])=[O:3])[CH2:17][CH2:18]1)=[O:12])([CH3:9])([CH3:8])[CH3:7]Participants
4
Procedure
Methanesulfonyl chloride (0.7 mL, 9.0 mmol) was added to a cooled solution of 4-(2-amino-ethyl)-piperazine-1-carboxylic acid tert-butyl ester (1.33 g, 5.8 mmol) in pyridine (25.0 mL). The reaction was stirred for 12 h and partitioned between partitioned between aqueous sodium bicarbonate and methylene chloride. The organic phase was washed with 1M hydrochloric acid, aqueous sodium bicarbonate, brine, dried over anhydrous magnesium sulfate and concentrated. Purification of the crude residue by flash chromatography over silica gel using 0-5% methanol in methylene chloride gave 4-(2-methanesulfonylamino-ethyl)-piperazine-1-carboxylic acid tert-butyl ester (0.70 g, 70%).