Reactions with Water and Other Nucleophiles

Pteridine, and substituted pteridines, are generally very thermally stable. However, because of the ready reaction with water, and other nucleophilic species, pteridines are unstable in hot solutions. Pteridine undergoes ring fission of the pyrimidine ring in aqueous acid to yield 3-aminopyrazine-2-carbaldehyde 11 (aqueous base yields 10). Such ring fission has been reviewed,28,29 and is discussed further in Section 7.3.1.4.7.2. 

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