Heterocyclic n-acetoxyarylamines, models for the putative ultimate carcinogens of aromatic amines: 2-acetoxyamino-5-phenylpyridine and 2-acetoxyamino-pyridine

Article abstract of DOI:10.1107/S0108270196015168

The structures of O-acetyl-N-(5-phenyl-2-pyridyl)-hydroxylamine, C₁₃H₁₂N₂O₂, (I), and O-acetyl-N-(2-pyridyl) hydroxylamine, C₇H₈N₂O₂, (II), have been determined in order to confirm earlier structure assignments based on spectroscopic information. Compound (I) is the probable mutagenic metabolite of the phenylalanine pyrolysis product 2-amino-5-phenyl-pyridine. The crystal structures of (I) and (II) are the first reported for heterocyclic N-acetoxyarylamines, the corresponding homocyclic arylamine derivatives being extremely unstable. In the solid state, both (I) and (II) exist as hydrogen-bonded dimers, with the arylamine N atom acting as donor and the pyridine N atom of a neighboring inversion-related molecule as acceptor; the distance between donor and acceptor N atoms is 3.007 (2) in (I) and 2.956(2) angstrom in (II). This orientation of the N - H bond results in the rotation of the acetoxy group out of the plane of the pyridine ring by 22.5 (2) in (I) and 27.4(2)° in (II).