The general procedure for the synthesis of 1-methylsulfonyl-4-aminopiperidine hydrochloride from 1-MS-4-Boc-aminopiperidine was as follows: 4-(N-Boc-amino)-1-methanesulfonylpiperidine (3.1 g, 11.15 mmol) was dissolved in 4 M HCl/dioxane solution (40 ml) and the reaction was stirred for 24 h at room temperature. After completion of the reaction, the reaction mixture was concentrated in vacuum. The resulting residue was azeotropically dried by mixing with toluene:methanol (1:1, v/v) to give the final 1-methylsulfonyl-piperidin-4-ylamine hydrochloride as a white solid (2.4 g, 100% yield).
