Heterocyclic studies. Part VI. Some 2-substituted derivatives of ethyl pteridine-4-carboxylate

Abstract

Syntheses of seven 2-substituted derivatives of ethyl pteridine-4-carboxylate (III; X = Cl, OH, OEt, NH₂, NMe₂ SH, or SMe) are described. The 2-hydroxy- and 2-mercapto-derivatives were obtained as 3,4-covalently hydrated species and the latter could not be dehydrated. The other compounds were prepared both as anhydrous and 5,6:7,8-dihydrated species, which were interconvertible. The influence of the 2-substituent on the position and extent of hydration is discussed. ¹H N.m.r. spectra are recorded.