Design, Synthesis and Biological Evaluation of Potent Antioxidant 1-(2,5-Dimethoxybenzyl)-4-arylpiperazines and N -Azolyl Substituted 2-(4-Arylpiperazin-1-yl)

Spontaneous conversion of O-tosylates of 2-(piperazin-1-yl)ethanols into chlorides during classical tosylation procedure

A direct conversion of piperazinyl ethanols into chlorides via a classical O-tosylation protocol is observed. The acceleration of the transformation by the piperazine unit is demonstrated. It is found that the reaction goes via the corresponding O-tosylate, which converts spontaneously into chloride with different rate depending on the substrate structure. In the case of pirlindole derivative, partially aromatized chloride formation was observed upon prolongation and/or increased excess of tosyl chloride.