Carboxylate, pyridine

Selenolo[2,3-b]pyridine-2-carboxylic acid, 3-hydroxy-synthesis, 4, 1034 Selenolopyridines, 4, 1034—1036 H NMR, 4, 1035, 1036 Selenolo[2,3-c]pyridines synthesis, 4, 1035 Selenolo[3,2-b]pyridines deuteriodeprotonation, 4, 1035 synthesis, 4, 1034 Selenolo[3,2-c]pyridines synthesis, 4, 1035 Selenolo[2,3-b]pyrroles ionization potentials, 4, 1046 Selenolo[3,2-b]pyrroles ionization potentials, 4, 1046 Selenolo[3,4-c]pyrroles non-classical... 

Thieno[2,3-6]pyridine-2-carboxylic acid, 3-amino-synthesis, 4, 1005... 

Constitution. When coniine is distilled with zinc dust or heated with silver acetate/ a new base, coiiyrine, CgH N, differing from coniine by six atoms of hydrogen, is formed. This on oxidation yields pyridine-2-carboxylic acid and, since it is not identical with 2-isopropylpyridine, must be 2-propylpyridine (I). When coniine is heated with hydriodic acid at 300° it yields w-octane (II). These and other observations due mainly to A. W. Hofmann, made it clear by 1885 that coniine was probably a-propylpiperidine (III), and this has been amply confirmed by other reactions of the alkaloid and by syntheses. Thus, Wolffenstein showed that on oxidation with hydrogen peroxide, coniine is converted into amino-w-propylvaleraldehyde (IV) ... 

An example of this type of cyclization is the formation of 3-nitro-l,5-naph-thyridin-4(lH)-one (4) from 3-(/3-nitroethylideneamino)pyridine 2-carboxylic acid (3) by heating in acetic anhydride [56JCS(I)212]. No yields are given. 

Pyridine-2-carboxylic acid is a structure element of the macrocycle 1,6-bis-deacetylevonine (Euonymus europaeus) (02CPB199). 

The rigid, planar pyridine analog 111 was isolated in low yield by first hydrolyzing the known (67) pyridine diethyl phosphonate 109 to the corresponding free acid 110 followed by permanganate oxidation (2). An alternative synthesis of 111 has recently been reported (68). Alkylation of pyridine-2-carboxylate -oxide with dimethylsulfate and subsequent reaction with the sodium salt of diethyl phosphite gave the triester 112, which was readily converted to 111. 

The photodegradation of the contact herbicide paraquat yielded many degradation products, but the major pathway produced l,2,3,4-tetrahydro-l-ketopyrido[l,2-fl]-5-pyrazinium that was further degraded to pyridine-2-carboxamide and pyridine-2-carboxylate (Figure 1.11) (Smith and Grove 1969). 

FIGURE 10.11 Interaction of pathways for degradation of pyridine-2-carboxylate, pyridine-3-carboxylate, and nicotine. (From Neilson, A.H. and Allard, A.-S., The Handbook of Environmental Chemistry, Springer, Heidelberg, 1998. With permission.)... 

Annibale, G., Canovese, L., Cattalini, L., Marangoni, G., Michelon, G. and Tobe, M.L. (1984) Displacement by chloride of pyridine-2-carboxylate from dichloro (pyridine-2-carboxylato) gold(111) in acidic solution the position of ring opening. Journal of the Chemical Society, Dalton Transactions, (8), 1641. 

Heating pyridine-2,3-dicarboxylic acid anhydride with l-ethyl-2-methylindole has been claimed to yield solely the pyridine-2-carboxylic acid, albeit in low yield. This then clearly reacts with Af,A/-diethyl-3-toluidine in acetic anhydride to give the 7-azaphthalide. This is surprising in view of a later report70 in which a one-pot process has been described. Heating pyridine-2,3-dicarboxylic anhydride, prepared in situ, with the indole and subsequent reaction with 3-/V,/V-diethylamino-phenetol under identical conditions to those used in Scheme 8 (but without intermediate isolations) produced a 20 1 mixture of the 4- and 7-azaisomers 16 and 17. It appears that in the previous report the major intermediate isomer, the pyridine-3-carboxylic acid, has not been isolated. 

Another example in which the free acid undergoes ready decarboxylation, but this time via a carbanion intermediate (50, actually an ylid), is pyridine-2-carboxylic acid (51), which is decarboxylated very much more readily that its 3- or 4-isomers ... 

The demetalating abilities of buffer species depend on both their structures and their acidities. Thus, while pyridine-2-carboxylic (picolinic) acid catalyzes the demetalation even of the rather inert lm, its 3- and 4-isomers (nicotinic and isonicotinic acids) are inactive. The difference is rationalized to result from the ability that only coordinated picolinic acid has to deliver a proton to an amidato nitrogen in an intramolecular manner. The reaction order in picolinic acid equals one for la and two for lm. For lm, inactive pyridine and nicotinic acid speed up the demetalation in the presence of picolinic acid (Fig. 8). 

Brief mentions of kinetics and mechanisms of reactions of nitrogen bases with a selection of palladium(II) complexes with ammine, amines, pyridine-2-carboxylate, pyridoxine, and related ligands are included in a review of analogous platinum(II) reactions (194). 

Pic, pyridine-2-carboxylate HMPA, hexamethylphosphoric triamide OEP, octaethylporphyrin. 

Of interest to note is that in previous studies, the kinetics of the substitution reactions with bidentate ligands as shown in Eqs. (34) and (35) have been reported, with Pic = pyridine-2-carboxylate (83) and phen = 1,10-phenanthroline (84)... 

Reactions between Ir(cod)(02CArN) (NArC02 = pyridine-2-carboxylate, isoquinoline-2-carboxylate, quinoline-2-carboxylate, pyrazine-2-carboxylate) and SiHPh3 result in the reversible formation of 80 or analogous complexes (cod = cycloocta-1,5-diene).267... 

Ceftazidime Ceftazidime is l-[[7-[[(2-amino-4-thiazolyl)[(l-carboxy-l-methylethoxy) imino]acetyl]amino]-2-carboxy-8-oxo-5-thia-l-azabicyclo[4.2.0]oct-2-en-3-yl]methyl]pyridin-2-carboxylic acid (32.1.2.82). As is the case in synthesis of ceftriazone, the synthesis of ceftazidime requires the preliminary synthesis of two starting compounds. 7-Amino-3-(l-pyridinomethyl)cef-3-en-carboxylic acid dihydrochloride is used... 

HPCA ([4-(3-heptyl)pyridine-2-carboxylic add]), transihon metal peroxides, 1116 15-HPETE (155 -hydroperoxy-5,811z,... 

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