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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: zhangh on September 29, 2006, 10:17:25 PM

Title: how to remove solvent DMSO when working up a nucleophilic substitution ?
Post by: zhangh on September 29, 2006, 10:17:25 PM

I am currently replacing chloro atom with an amine with DMSO as solvent, after the completion of the reaction, extraction  with EtOAc and washed with H2O, but some DMSO still in EA layer, how to remove DMSO efficientyl ? Thanks 

Title: Re: how to remove solvent DMSO when working up a nucleophilic substitution ?
Post by: HP on September 30, 2006, 04:39:51 AM

It;s possible to precipitate your amine product with dry HCl to convert it to NH3+Cl- salt which should be insoluble in EtAc (better crystalization at low temp)...Then you must wash the crystals with Et2O for example and vacuum dry. To free the amine and reisolate your product must add water/base/salt and reextract the pure amine with pure EtAc.