This compound can be prepared in two different ways: 1) By condensation of the sodium salt of o-sulfobenzoylimide (I) with 3-bromo-2-piperidone (II) in refluxing DMF (1). 2) By condensation of o-sulfobenzoic acid anhydride (III) with 3-amino-2-piperidone (IV) in refluxing xylene (2).