Pyrimidopyrimidines, substitution

The IR spectra of pyrimidopyrimidines are extremely similar to those of the isomeric pteri-dines.106 IR spectral data for amino- and anilino-substituted pyrimido[4,5-rf]pyrimidines indicate NH absorptions in the range of 3130-3470 cm-1 (see Table 16).108,113 114 The ring vibrations for tetra-substituted derivatives are observed in the range 1550-1600 cm-1.108... 

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