4-aminoazobenzene (1) from cold, alkaline digests of livers from rats fed the hepatocarcinogen, N, N-dimethyl-4-aminoazobenene (Z). 4 At the time when the identity of 1 was still unknown to us, we were struck by the disparity between its behavior on alumina chromatography (similar to that of tertiary aminoazo dyes) and its chemical behavior (as a secondary amine). Upon chromatography on carboxymethylcellulose in citric acid-ethanol ...
