HETEROCYCLIC N-ACETOXYARYLAMINES, MODELS FOR THE PUTATIVE ULTIMATE CARCINOGENS OF AROMATIC-AMINES - 2-ACETOXYAMINO-5-PHENYLPYRIDINE AND 2-ACETOXYAMINOPYRIDINE

The structures of O-acetyl-N-(5-phenyl-2-pyridyl)-hydroxylamine, C13H1 2N2O2, (I), and O-acetyl-N-(2-pyridyl)hydroxylamine, C7H8N2O2, (II), h ave been determined in order to confirm earlier structure assignments based on spectroscopic information. Compound (I) is the probable mutag enic metabolite of the phenylalanine pyrolysis product 2-amino-5-pheny l-pyridine, The crystal structures of (I) and (II) are the first repor ted for heterocyclic N-acetoxyarylamines, the corresponding homocyclic arylamine derivatives being extremely unstable. In the solid state, b oth (I) and (II) exist as hydrogen-bended dimers, with the arylamine N atom acting as donor and the pyridine N atom of a neighboring inversi on-related molecule as acceptor; the distance between donor and accept or N atoms is 3.007(2) in (I) and 2.956(2) Angstrom in (II). This orie ntation of the N-H bond results in the rotation of the acetoxy group o ut of the plane of the pyridine ring by 22.5(2) in (I) and 27.4(2)degr ees in (II).