Heterocyclic studies. Part X. 4-Phenylpteridine and some methyl derivatives

Abstract

Suitable nitration conditions for obtaining two mononitro- and two dinitro-derivatives of 2,4-dihydroxy-6-phenyl-pyrimidine are described. The 5-nitro-compound was converted into 4-phenylpteridine and its 2- and 7-methyl, 2,7- and 6,7-dimethyl, and 2,6,7-trimethyl derivatives.

None of the compounds was appreciably hydrated in aqueous solution as the neutral molecule but 4-phenyl-pteridine and its 2-methyl derivative formed 5,6,7,8-dihydrated cations. The compounds containing 6- or 7-methyl groups were unstable as cations and apparently underwent dimerisation and oxidation in strongly acidic solutions.