The Beckmann rearrangement is an organic reaction used to convert an oxime to an amide under acidic conditions. Methyl 5-cyanopyrazine-2-carboxylate uses The reaction begins by protonation of the alcohol group forming a better leaving group. ((2-Iodoethoxy)methyl)benzene uses The R group trans to the leaving group then migrates to the nitrogen, resulting in a carbocation and the release of a water molecule. This trans [1-2]-shift allows for the prediction of the regiochemistry of this reaction. The water molecule then attacks the carbocation and after deprotonation and tautomerization results in the final amide product. ^[1]