David Nalewajek

Controlled, regiospecific oxidation of pyridine carboxylic acids and esters with elemental fluorine

Abstract Pyridine carboxylic acid salts or esters in water or water—acetonitrile mixtures were treated with elemental fluorine to give the corresponding 2-pyridones.

Preparation, crystal and molecular structure and properties of 5,5′-bis-(1,3-dithiol-2-ylidene)[bicyclopenta-1,3-dien-1-yl]-2,2′,3,3′-tetracarbonitrile

The synthesis and properties of 2-(3,4-dicyanocyclopenta-2,4-dienylidene)-1,3-dithiole 2have been, previously reported. NMR spectral data of that compound imply a large contribution of the dipolar form to its electronic structure. Two-solvent diffusion recrystallization, in the presence of O2, yields the title compound 3, the crystal structure of which is reported here. This appears to be the first crystal structure of a compound containing the dicyanocyclopentadiene moiety. The space group is P1–, and the lattice parameters are a= 8.3617(19), b= 11.1196(23). c= 12.8159(20)A, α= 96.587(15)°, β= 103.103(15)°, γ= 109.917(16)° and V= 1066.9(4)A°3 for Z= 2. We also discuss a plausible mechanism for the formation of compound 3, and its spectral properties.