Acyl Derivatives of Aminopyrazines

Aminopyrazines may be acetylated under a variety of conditions that mostly use acetic anhydride alone or in admixture with acetic acid, pyridine, or perchloric acid to give the following acetamidopyrazines (with reaction conditions) 2-acetamido-3-carbamoylpyrazine (acetic anhydride-acetic acid at I007l0h) (1175)  

Aminopyrazine jV-oxides may rearrange and acetylate in the presence of acetic anhydride. Thus 2-amino-3 yanopyrazine 1-oxide with acetic anhydride and acetic acid at reflux for 2 hours gave 3.acetamido-2-carbamoyl-5-hydroxypyrazine (25), 2-amino-3 thoxycarbonylpyrazine 1-oxide similarly treated gave 3-acetamido-2-ethoxycarbonyl-54iydroxypyrazine (538), and 2-amino-3 yano-5-methylpyrazine 

1- oxide with trifluoroacetic acid-trifluoroacetic anhydride gave 2-carbamoyl-5-hydroxy-6-methyl-3-trifluoroacetamidopyrazine (538). 

2-Aminopyrazine with acetonitrile in the presence of aluminum chloride formed 

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