Synthesis, Characterization, and Optimum Reaction Conditions of Oligo-3-Aminopyridine and its Schiff Base Oligomer

Abstract

The products and the oxidative polycondensation reaction conditions of oligo-3-aminopyridine with H 2 O 2 and NaOCl were studied. In this reaction, NaOCl was observed to be more active than H 2 O 2 and optimum reaction conditions were determined. Oligo-3-aminopyridine (OAP) was synthesized from the oxidative polycondensation of 3-aminopyridine (AP) with NaOCl and H 2 O 2 in an aqueous acidic medium at 25 -90 C. The products were characterized by 1 H NMR, FT-IR, UV-Vis, and elemental analysis. The number-average molecular weight, weight-average molecular weight, and polydispersity index values of OAP synthesized were found to be 250, 800 g mol À1 , and 3.20, respectively, using NaOCl, and 240, 840 g mol À1 , and 3.50, respectively, using H 2 O 2 . The respective values of the Schiff base were 1140, 5190 g mol À1 , and 4.55. At optimum reaction conditions, yields of the reaction products were 80.1% (H 2 O 2 ) and 82.0% (NaOCl). About 90% AP was converted into OAP. TG analyses showed that OAP was stable towards thermo-oxidative decomposition. The weight loss of OAP was found to be 5, 50, and 92 at 125 , 617 , and 1000 C, respectively. The weight loss of oligo-aminopyridinylazomethinephenol (OAPAP) was found to be 5, 50, and 80.50 at 175 , 660 , and 1000 C, respectively. Also, a new oligomeric Schiff base was synthesized from the condensation of OAP with salicylaldehyde and their structures and properties were determined.

Ketimine substituted polyphenol: Synthesis, characterization and investigation of its thermal and electrochemical properties

“…The loss of mass at the rate of 16.3% corresponds approximately to the sum of masses of OH ve CH 3 groups in the polymer structure. When the value of carbon residue at the rate of 83.7% which was obtained for poly(3‐PHEP) is compared with the values obtained for o ‐substituted,6, 17–30, 37 m ‐substituted7 and p ‐substituted8–15, 40, 41 poly(phenoxy‐imine)s in literature, it can be seen that the highest value belongs to poly(3‐PHEP). Having this feature, poly(3‐PHEP) step forwards in comparison with imine‐substituted polyphenols.…”

“…Imines polymers which have a lot of functionality groups can be used for cleaning poisonous heavy metals in industrial waste waters. So far, poly(phenoxy‐imine)s and their derivates have been synthesized by oxidative polycondensation method, and their properties have been extensively investigated,7–30 but surprisingly, synthesis of poly(phenoxy‐ketimine)s and their thermal properties have not been reported yet. …”

Synthesize and Characterization of 2‐Aminothiazole Monomer and Polymer‐based Bifunctional Fe/N/C Catalysts for Oxygen and Carbon Dioxide Reduction Reactions

“…The synthesis procedures of AT‐polymer‐Fe/N/C and AT‐monomer‐Fe/N/C are illustrated in Figure . In brief, the 2‐aminothiazole polymer was obtained from the polymerization of 2‐aminothiazole by hydrothermal synthesis . Then, AT‐polymer‐Fe/N/C catalyst was prepared by heat‐treating the mixture consisting of FeCl 3 , KJ600 carbon black, and 2‐aminothiazole polymers in an inert gas atmosphere.…”

Molecular weight dependent antistaphylococcal activities of oligomers/polymers synthesized from 3-aminopyridine

“…In a previous study, a smaller oligomer of 3--aminopyridine (OAP) was synthesized, characterized and the M n , M w and polydispersity index (PDI) values were found to be 250 and 800 g mol -1 and 3.20, respectively. 9 When 50 μg of this OAP was used, the inhibition zone was 17 mm in the disc diffusion assay and the MIC was found to be 25 μg mL -1 in broth macrodilution assay. 8 These values for this oligomer were included in Table II just for comparison.…”

“…9 The polymerizations were performed in 250 mL three-necked round-bottom flasks which were fitted with a condenser, thermometer and magnetic stirrer. Alkaline and acid media were realized using aqueous solutions of KOH and CH 3 COOH, respectively.…”