Presence of Amino and Other Groups

2-Aminopyrazine with bromine in acetic acid gave 2-amino-3,5-dibromopyrazine (804, 810, 811), also obtained from bromination of 2-amino-3-bromopyrazine in aqueous hydrobromic acid (806, 807), and 5-amino-2,3-dimethylpyrazine with bromine in acetic acid gave 2-amino-3-bromo-5,6-dimethylpyrazine (812). 2-Amino-5-phenylpyrazine with bromine and pyridine in chloroform at 20 gave 2-amino-3-bromo-5-phenylpyrazine (365a), and 2-amino-3-chloropyrazine with 20% hydrobromic acid and bromine gave 2-amino-5-bromo-3-chloropyrazine (806,807). 

2-Chloro-3-morpholinopyrazine treated with allyl alcohol followed by bromination in the presence of water has been shown to give 5-bromo-2-(3 -bromo-2-hydroxypropoxy)-3-morpholinopyrazine (813), and bromination of 2-amino[or 2-(p-toluenesulfonamido)]-3-methoxypyrazine with a mixture of potassium bromide and bromate in 6N sulfuric acid gave 2-amino-[or 2-(p-toluenesulfonamido)]-5-bromo-3-methoxypyrazine (814). The bromination (814) of 2-methoxy-3-sulfanilamidopyrazine in methanol was anomalous (815,816) [see Section 5D(2)]. 

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