Clayfen Ritter reaction

The scope of the Ritter reaction can also be extended by avoiding strong acid as the carbenium ion initiator. In at least one case it is possible to omit this reagent entirely because of the facility of 5 1 reaction. Thus, reflux of r-butyl bromide in acetonitrile or propionitrile for 24 h led to formation of A -f-butylamide products. Less commonly used initiators have included cation exchange resins and clayfen. In this latter case, the clay-supported iron(III) nitrate is believed to give rise to nitrosonium ions, which react with the alkyl halide substrate to produce a carbenium ion. Yields of amide from this technique are generally modest (21-35%). 

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