| Abstract: | The three-component synthesis of 4,6-diamino-1-aryl-1,2-dihydro-2,2-dimethyl-s-triazines from arylamines. cyanoguanidine, and acetone has been studied by nmr spectral analysis in trifluoro-acetic acid solution. The presence of 2-guanidino-4-methylquinazoline contaminants can be discerned clearly at concentrations as low as 1%. Arylamines most likely to give significant proportions of guanidinoquinazoline byproducts are 2-naphthylamines and anilines containing one or more electron-donating meta-substituents. |
