Lawesson's reagent → 1-(4-Amino-2-methylphenyl)piperidine-2-thione

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Reaction Steps

10 g (48.95 mmol) of 1-(4-amino-2-methylphenyl)piperidin-2-one are heated to the boil in 70 ml of anhydrous toluene together with 9.9 g (24.48 mmol) of 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide (Lawesson's reagent). After 40 minutes, the solvent is removed, and the residue is taken up in dichloromethane (DCM)/1 M aqueous hydrochloric acid. After repeated washing with DCM, a pH of 12 is set using conc. sodium hydroxide solution. Extraction with DCM, drying over Na2SO4 and evaporation of the solvent give 9.25 g (41.98 mmol) of 1-(4-amino-2-methylphenyl)piperidine-2-thione.

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