The Characteristic IR Spectra of 6-Aryl-4(3H)-Pteridinones

The 6-Aryl-4(3H)-pteridinones and 2-amino-3-carbamoyl-5-phenylpyrazines, and their p-substitute of the phenyl series compounds were synthesized. Their IR spectra have been determined and the relations between the structures and the IR data have been studied. The results showed that the νC- H and δC-H vibration of the phenyl was affected by different substituted groups attached on it, and bromine and chlorine have the same effect. We have pointed out the range of phenyl C-X vibration on the spectra, and it was also found that the spectra have changed notably after the cyclization. We can quickly and accurately determine whether the acyl was cyclized to lactam or not by IR spectra with the data in this article.