2-Amino-5-bromo-3-methoxypyrazine

Crystal structures of 3,5,6-tri-t-butyl-2-hydroxypyrazine (1093) 2,5-dichloro-3-methoxypyrazine (915) and 2,3-dichloro-5-ethylamino-6-methoxypyrazine (916) have been determined. The dipole moment of 2-amino-5-bromo-3-methoxypyrazine (2.94D in benzene) is consistent with the S-cis configuration (52) (749) and the polarographic behavior of 3-hydroxy(and methoxy)-2,5-dimethylpyrazine (and their A(-oxides) at various pH values has been investigated (588). 

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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