[{"from": "human", "value": "Provide a description of this molecule. [C][=C][C][=Branch1][P][=C][C][=C][Ring1][=Branch1][C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][N][N]"}, {"from": "gpt", "value": "The molecule is the organic compound with the formula (C6H4NH2)2. it is an aromatic amine. It is prepared in a two step process from nitrobenzene. First, the nitrobenzene is converted to 1,2-diphenylhydrazine, usually using iron powder as the reducing agent. Treatment of this hydrazine with mineral acids induces a rearrangement reaction to 4,4'-benzidine. Smaller amounts of other isomers are also formed. The benzidine rearrangement, which proceeds intramolecularly, is a classic mechanistic puzzle in organic chemistry.  This aromatic amine is a component of a test for cyanide and also in the production of dyes. Benzidine has been linked to bladder and pancreatic cancer. Since August 2010 benzidine dyes are included in the EPA's List of Chemicals of Concern."}]