Azidolysis of Nuclear Halogenopyrazines

It should be remembered that nearly all azidopyrazines exist in equilibrium with their tetrazolo[l,5-e]pyrazine forms (168) however, all such compounds are called azidopyrazines here. The following examples show the conditions and yields for typical transformations of halogeno- into azidopyrazines  

2-Chloro-3,6-dimethylpyrazine (169) gave 2-azido-3,6-dimethylpyrazine (170) (NaN3, Me2NCHO, reflux, 10 h 83% 1314 or NaN3, Me2NCHO, 100°C, 24 h 80%) 231 also analogous products.232,242,1314 

Methyl 3-chloro-2-pyrazinecarboxylate (173, R = Cl) gave methyl 3-azido-2-pyrazinecarboxylate (173, R = N3) (NaN3, Me2NCHO, 120°C, N2, 1 h  

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