Table 1* 



Parent molecule 

 X=CH3 



Carcino- 

 genic 



potency 



(rat 



liver) 



Ref. 



Split product 

 X=CH3 



X 



■N=N 



•N< 



X 



X 



4,5'-Dimethyl-iV-iV-diinetliylamino- 

 azobenzene 



X 



H2N 



N<^ 



-N=N- 

 Aminoazobenzene 



-NH, 



10 



HoN 



NH2 



X X 



2,3'-Dimethylaminoazobenzene 



NH2 



+ 



11 



H2N 



X 



NH2 



N=N' 



■N< 



+ 



4,6'-Dimetliyl-iV-A^-dimethylamino- 

 azobenzene 



X 



H2N 



■N< 



< 



•N-:N- 



++ 



12 



iV-A^-dimethylaminoazobenzene 



H2N 



X 



•N< 



+ + 



4-Methyl-A^-iV-dimethylaminoazo- 

 benzene 



H2N- 



X 



X 



H 



CH3OC 



N- 



n/ 



* The table on these facing pages presents the results of tests showing the 

 apparent correlation between the carcinogenic properties of the parent azo com- 

 pounds and the toxic properties of the p-aromatic diamine split product of these 

 molecules. 



248 



