Results 2, 6-and 4, 6-disubstituted and 2, 4, 6-trisubstituted pyrimidines exhibit a maximum in the region of 264* 6 mp (Fig. 1); the 2, 4, 6-tri-substituted-5formamidopyrimidines possess a band at 265* 6 rnp. In a homogeneous series, the molecular extinction coefficients decrease in the order: 2, 4, 6-trisubstituted> 2, 4, 6-trisubstituted-5-formamido> 4, 6- disubstituted> 2, 6-disubstituted. In both the 2, 6-and 4, 6-disubstituted pyrimidines an ...
