N-Diethyl-m-toluamide The Insect Repellent OFF

In this experiment, you will synthesize the active ingredient of the insect repellent OFF, N,N-diethyl-m-toluamide. This substance belongs to the class of compounds called amides. Amides have the generalized structure 

The amide to be prepared in this experiment is a disubstituted amide. That is, two of the hydrogens on the amide—NHj group have been replaced with ethyl groups. Amides cannot be prepared directly by mixing a carboxylic acid with an amine. If an acid and an amine are mixed, an acid-base reaction occurs, giving the conjugate base of the acid, which will not react further while in solution  

However, if the amine salt is isolated as a crystalline solid and strongly heated, the amide can be prepared  

Because of the high temperature required for this reaction, this is not a convenient laboratory method. 

Amides are usually prepared via the acid chloride, as in this experiment. In step 1, ffj-toluic acid is converted to its acid chloride derivative using thionyl chloride (SOCI2). 

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