Reactions of 2-amino-5-arylazopyrimidine derivatives and phenyl isocyanate

3-Arylhydrazono-2,4-pentanediones and 3,3'-(phenylene-1,4-dihydrazono)bis(pentane-2,4-dione) was synthesized by azo coupling of the acetylacetone with aryldiazonium chlorides and phenylene-1,4-bis(diazonium) dichloride. 2-Amino-4,6-dimethyl-5-arylazopyrimidines and 5,5'-(phenylene-1,4-diazo)bis(2-amino-4,6-dimethylpyrimidine) have been prepared from the same diketones and guanidinium carbonate. 2-Aminopyrimidine derivatives add phenyl isocyanate to give the N,N'-disubstituted ureas. The structure of the resulted products was confirmed by determination of the melting point and spectrophotometric techniques such as IR and 1H-NMR, in some cases by using 13C-NMR spectroscopy.