Esters of pyridine-2,6-dicarboxylic acid

The Ni - and Zn " " -complexes of phenyl and salicyl esters of pyridine-2,6-dicarboxylic acid [50a and b] hydrolyse much faster than the uncomplexed esters (Breslow and McAllister, 1971) the rate of hydroxide ion catalysis of the Ni " -complexes increases 9300... 

Let us examine few models. The rate of hydrolysis of the ester function of the phenyl and salicyl esters of pyridine-2,6-dicarboxylic acid is significantly enhanced upon complexation with Ni(II) or Zn(II) ions (225). 

The catalytic effect of nickel(n) on hydrolysis rates of the salicyl and phenyl esters of pyridine-2,6-dicarboxylic acid is ascribed to the intermediacy of a 1 1 complex between the ester and the nickel(n). Rates of hydrolysis and of reaction with hydroxide are reported.Kinetic and equilibrium studies have... 

Vinyl esters of pyridine-2,5- and 2,6-dicarboxylic acids were prepared from the diacid chlorides and mercuriacetaldehyde. The allyl and propargylic esters of pyridine 2,4- and 2,6-diacids were prepared similarly from the alcohols. ... 

This reaction consists of the condensation of two molecular equivalents of a 1,3 diketone (or a J3-keto-ester) with one equivalent of an aldehyde and one of ammonia. Thus the interaction of ethyl acetoacetate and acetaldehyde and ammonia affords the 1,4-dihy dro-pyridine derivative (1), which when boiled with dilute nitric acid readily undergoes dehydrogenation and aromatisation" to gb e the diethyl ester of collidine (or 2,4,6-trimethyl-pyridine-3,5 dicarboxylic acid (II)). For the initial condensation the solid aldehyde-ammonia can conveniently be used in place of the separate reagents. 

The oxidative degradation of pyrido[3,4-6]pyrazine, as well as its 2,3-dimethyl derivative, by potassium permanganate occurs at the pyridine moiety, thus producing pyrazine-2,3-di-carboxylic acid and 5.6-dimethylpyrazine-2,3-dicarboxylic acid, respectively, isolated as the diethyl esters.67... 

Bennasar extended his research on 2- and 3-indolylacyl radicals to intramolecular cyclizations to yield 2,3-fused indoles [112], Under nomeductive conditions (n-Bu6Sn2, hv), radical 201 underwent a cascade addition-oxidative cyclization sequence with a number of alkene acceptors including dimethyl fumarate (45%), methyl 1-cyclohexenecarboxylate (53%), methyl crotonate (71%), vinyl sulfone (22%), and the a,p-unsaturated lactam ester, 2-oxo-5,6-dihydro-2H-pyridine-l,3-dicarboxylic acid dibenzyl ester (41%) to form cyclopenta[h]indol-3-ones 202. Reaction of 201 with acrylonitrile and methyl acrylate, however, generated cyclo-hepta[h]indoles, the products of bis-addition-cyclization sequences. 

Pyridonecarboxylic acid esters. F2 (diluted with N2) bubbled into a soln. of dimethyl pyridine-2,3-dicarboxylate in 2 1 acetonitrile/water for 20 min at 0 , flushed with N2 for 30 min at room temp., and refluxed for 2 h-+ dimethyl 1,6-dihydro-6-oxopyridine-2,3-dicarboxylate. Y 56%. F.e. inch oxidation of 2-, 3- and 4-carboxypyridines, and of methyl quinoline-4-carboxylate, s. M. Van Der Puy et al.. Tetrahedron Letters 29, 4389-92 (1988). 

Pvridine Dicarboxvlic Hvdrazide A mixture of 100 ml. of benzene, 15 g. of hydrazine hydrate, and 28 g. of 2,5-pyridine dicarboxylic acid methyl ester was heated at reflux on a steam bath for 24 hrs. The mixture was cooled and diluted with 200 ml. of methanol and the finely crystalline product collected. This was dissolved in 1500 ml. of water at the boil, and decolorized with charcoal. About half of the water was removed by evaporation and the product allowed to crystallize. The yield was 22.6 g. m.p. 279-280. Anal. Calcd. for C7H9O2N5 C, 42.9 H, 4.62 N, 35.7. Found ... 

The polyamide obtained by polycondensation of 2,6-diaminopyridine and 2,6-pyridine dicarboxylic acid was the first polymer to assemble itself into a double helix (DNA-type) in solution. The synthesis and physicochemical characterization of some polymer-supported rhodium catalysts based on polyamides containing 2,6- and 2,5-pyridine units were reported by Michalska and Strzelec (2000) these catalysts were used for the hydrosilylation of vinyl compounds such as phenylacetylene. Chevallier et al. (2002) prepared polyamide-esters from 2,6-pyridine dicarboxylic acid and thanolamine derivatives and investigated their polymer sorption behavior towards heavy metal ions. Finally, Scorlanu et al. (2006) also prepared a polymer with improved performance based on polyureas containing 2,6-pyridine moiety and polyparabanic acids, and polymethane-ureas containing 2,6-pyridine rings. 

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