organic compounds
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 to confirm earlier structure assignments based on spectroscopic information. Compound (I) is the probable mutagenic metabolite of the phenylalanine pyrolysis product, 2-amino-5-phenylpyridine. 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) Å in (I) and 2.956.(2) Å 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).