ChemInform Abstract: COMPLEXES BETWEEN NEUTRAL MOLECULES. V. UREA, THIOUREA AND MALONODINITRILE COMPLEXES OF NONCYCLIC CROWN‐TYPE POLYETHERS WITH PYRIDINE N‐OXIDE SUBUNITS

Abstract

Die acyclischen Kronenetheranalogen (I) und (II) mit Pyridin‐N‐oxid‐Einheiten werden durch die Umsetzung von 2,6‐Bis‐[brommethyl]‐pyridin‐N‐oxid mit den entsprechenden aromatischen Hydroxyverbindungen im Fall von (Ia) und (II) bzw. durch Oxidation der entsprechenden Pyridin‐Analogen mit m‐Chlorperbenzoesäure im Fall von (Ib‐d) synthetisiert.

Covalently Immobilizable Tris(Pyridino)-Crown Ether for Separation of Amines Based on Their Degree of Substitution

“…The multistep synthesis of macrocycle 1 was started with the commercially available 2,6-dimethylpyridine, which was converted to 2,6-pyridinedimethanol (2) according to a reported procedure [11]. Bispyridine diol 10, the key intermediate of the synthesis, has previously been reported, but it was prepared by more complicated procedures [10,11,[24][25][26][27][28]. We report here an improved and optimized synthetic pathway for obtaining diol 10, and we also fully characterized it.…”

“…All the structural classes of the selected model compounds contained three analogues of different degree of N-substitution. Further studies were carried out on the extendibility of the separation by investigating the discriminative power toward some bioactive small-molecule amines (see D in Figure 3), e.g., octopamine (24), synephrine (25), norepinephrine (26) and ephedrine (27) containing additional substituents in both aliphatic and aromatic units. This supplement was also useful to provide information about the influence of additional substituents on coordination of the protonated amines.…”

“…This supplement was also useful to provide information about the influence of additional substituents on coordination of the protonated amines. The studied model amines (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27) and the logarithms of the determined stability constants of the complexes are summarized in Figure 3. The least stable complexes were obtained in the cases of aliphatic amines (A in Figure 3); probably due to the lack of π-π interaction inside the complex, which takes place in all the other cases (B-D).…”

“…4.2.9. Preparation of 3,11,26,3.1.1 5,9 .1 13,17 ]heptacosa-1(24),5,7,9 (27), 13,15,17(26),21 (25),22-nonaen-7-ol (14) A solution of 1 (0.50 g, 1.06 mmol) in toluene (100 mL) was hydrogenated in the presence of Pd/C catalyst (0.10 g, Pd/charcoal; activated, 10% Pd) at 50 • C. After 8 h the reaction was complete. The catalyst was filtered off and washed with methanol (2 × 50 mL).…”