Amino-methylamine exchange

In addition to amino-methylamine exchanges, amino-benzylamine exchanges were found. When iv-benzyl salts of pyrimidine, 4,6-dimethyl-pyrimidine, and 4-t-butylpyrimidine react with liquid ammonia, the respective debenzylated compounds were isolated (Scheme III.9) (82JHC3739). 

Both chloro substituents in 2,3-dichloropyrido[2,3-/>]pyrazine are exchanged for methyl-amino groups by reaction with methylamine.79 As in examples of the pyridopyrimidine series,80 exchangeable substituents such as chloro are generally the more reactive ones in the diazine moiety. Thus, in 2,6-dichloropyrido[2,3-6]pyrazine (15), only the 2-chloro group is substituted by hydrazine under the conditions given.34... 

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