CHEMISTRY OF HETEROCYCLIC-COMPOUNDS .42. NICOTINIC-ACID CROWN ETHERS - SYNTHESIS, REACTIONS, AND COMPLEXATION OF NICOTINONITRILE MACROCYCLES

2, 6-Dichloronicotinamide (6), prepared from the corresponding disubstituted nicotinic acid, was dehydrated with refluxing thionyl chloride to give the nitrile 8, which was subsequently converted into the 1 : 1 macrocyclic nicotinonitriles 9. Isomeric macrocyclic dimers 10 were also isolated from the reaction. NMR and mass spectral data were used to ascertain the macrocyclic structures. Eu(fod)3 shift reagent was employed to demonstrate that the predominant site of europium ion coordination in these nitrile macrocycles is the central bridging ethereal oxygens. Reduction of 9b with lithium aluminum hydride or Vitride gave fragmentation of the macrocyclic ring nucleus resulting in formation of pentaethylene glycol and reduction products derived from the pyridine nucleus. © 1979, American Chemical Society. All rights reserved.