Methyl 2-pyridinecarboxylate

Carbonylation of chloropyridines is less straightforward than that of bromo- and iodopyridines. The a and y positions are sufficiently activated to undergo facile oxidative addition to Pd(0), whereas the reactivity is greatly diminished at (3 positions. Thus, 2,6-dichloropyridine was converted to the corresponding dimethyl ester in good yield under normal Pd-catalyzed carbonylation conditions [152], and 2-chloropyridine was readily carbonylated to furnish methyl 2-pyridinecarboxylate (191), but 3-chloropyridine gave no carbonylated products under the same conditions [153,154],... 

Streptonegrin (negrin, 5-amino-6-[7-amino-5,8-dihydro-6-methoxy-5,8-dioxo-2-quinolinyl]-4-[2-hydroxy-3,4-dimethoxyphenyl]-3-methyl-2-pyridinecarboxylic acid) [3930-19-6] M 506.5, m 262-263°, 275°(dec). Purified by TLC on pH 7-buffered silica gel (made from a slurry of Silica Gel 60 and 4(X)ml of 0.05M phosphate buffer pH 7.0) and eluted with 5% MeOH/CHClj. The extracted band can then be recrystd from Me2CO or dioxane as almost black plates or needles. It is soluble in pyridine, Me2NCHO, aqueous NaHCOy (some dec), and slightly soluble in MeOH, EtOH, EtOAc and H2O. It has a pKa value in the range 6.2-6.4 (dioxane/H2O 1 1) and UV 248, 375-380nm (e 38400 and 17400). [Weinreb et al. JACS 104 536 1982 Rao et al. JACS 85 2532 1963]. It is an antineoplastic and causes severe bone marrow depression [Wilson et al. Antibiot Chemother 11 147 7967]. 

Pyridinecarboxyiic) (3-Pyridinecarboxylic) (4-Pyridinecarboxylic) (2,6-Pyridinedicarboxylic) (6-Methyl-2-pyridinecarboxylic)... 

Streptonigrin. S-Amino-6-(7-amino-5,8-dihydro-6-methoxyS,8-dioxo-2-quinolyl)-4-( 2-hydroxy-3,4-dimetk-oxyphenyl)-3-methyl-2-pyridinecarboxylic acid 5-amino-6-(7-amiito-S,8-dihydro-6-methoxy-S,8-dioxo-2-qulitolyl)-4-(2-hydroxy-3,4-dimethoxyphenyl)-3-methylptcolinic acid bruneomycin NSC 45383 Nigrin. Cj,H, 7N408 mol wt 506.46. C 59.28%, H 4.38%, N 11.06%, O 25.27%. Antitumor antibiotic produced by Streptomyces flocculus Rao,... 

Methyl 2-pyridinecarboxylate irradiated 2 min. at 32° under Ng with 254 nm light in methanol containing some H2SO4 -> methyl 6-methoxy-2-pyridine-carboxylate. Y 95%. F. e. s. T. Sugiyama et al., Tetrah. Let. 1974, 4339. 

Methylamino)benzoic acid, in A-00105 2-Methylbenzohydroxamic acid, M-00135 4-Methylbenzohydroxamic acid, M-00136 6-Methyl-2-pyridinecarboxylic acid Me ester, in M-00271... 

The question of additivity of SCS is difficult to probe, because ortho interactions, notoriously difficult to account for, are bound to arise in even disubstituted pyridine rings, apart from those with the 3,5-disposition. To test this, proton chemical shifts have been measured for six series of substituted methyl pyridinecarboxylates (71), (72), (73), (74), (75) and (76) <750MR(7)4l), and SCS ortho and para can be accounted for by assuming additive substituent, ester, and nitrogen effects. However, for protons meta to the substituent, particularly for the case where both the proton and the substituent are adjacent to N, the additivity breaks down, and there is evidence of substituent-nitrogen interactions. 

Methyl pyridinecarboxylates can be converted to the corresponding amide on treatment with MgCl2 or MgBr2 in the presence of a range of primary and secondary amines <2001TL1843>. The reaction of the dimethyl pyridine-2,3-dicarboxylate with the 2,5-isomer occurs selectively at the 2-position. 

As the reactivity of a function group depends on the structure of the molecule as a whole, and particularly on the nearest neighbours, the reaction used and the reaction conditions in the determination of a functional group depend on the type of compound. Thus, several methods of methylating pyridinecarboxylic acids have been compared... 

Pyridine 210 is oxidized by 20% nitric acid at the acetyl group to 2-methyl-5-pyridinecarboxylic acid, while its ozonation gives cinchomeronic acid [pyridine-2,5-dicarboxylic acid (215)] (75DIS) which is decarboxylated (200°C, 2 h) to nicotinic acid 216 in 97% yield (75DIS). 

Chemical Name 3-pyridinecarboxylic acid 2,2-bis[[(3-pyridinylcarbonyl)oxy] methyl]-1,3-propanediyl ester... 

Niacin methyl ester nicometh 3-carbomethoxypyridine methyl 3-pyridinecarboxylate 3-pyridinecarboxylic acid methyl ester... 

CN 3-pyridinecarboxylic acid 2-[2-(4-chlorophenoxy)-2-methyl-l-oxopropoxy]ethyl ester... 

RN 70-19-9 MF Ci.HijNOj MW 207.23 EINECS 200-727-5 CN 3-pyridinecarboxylic acid (tetrahydro-2-furanyl)methyl ester... 

The cycloadducts formed from the Diels-Alder reaction of 3-amino-5-chloro-2(17/)-pyrazinones with methyl acrylate in toluene are subject to two alternative modes of ring transformation yielding either methyl 6-cyano-l,2-dihydro-2-oxo-4-pyridinecarboxylates or the corresponding 3-amino-6-cyano-l,2,5,6-tetrahydro-2-oxo-4-pyridinecarboxylates. From the latter compounds, 3-amino-2-pyridones can be generated through subsequent loss of HCN <96 JOC(61)304>. Synthesis of 3-spirocyclopropane-4-pyridone and furo[2,3-c]pyridine derivatives can be achieved by the thermal rearrangement of nitrone and nitrile oxide cycloadducts of bicyclopropylidene <96JCX (61)1665>. 

Similar ring systems were prepared <97JHC1693> by Coppo and Fawzi from the reaction of substituted ethyl 5-[methyl(methylsulfonyl)amino]-l 7/-pyrazole-4-carboxylates 119 with sodium hydride. This gave the 7-substitued 1,7-dihydro-l-methylpyrazolo[3,4-c][l, 2]thiazin-4(37/)-one 2,2-dioxides 120 in fair to good yield (Scheme 30). They also extended this synthesis by treating methyl 2-[methyl(methylsulfonyl)amino]-6-(trifluoromethyl)-3-pyridinecarboxylate 121 with sodium hydride in dimethylformamide to yield l-methyl-7-(trifhioromethyl)-l//-pyrido[2,3-c][l,2]thiazin-4(3//)-one 2,2-dioxide 122 in 79% yield (Scheme 31) <98JHC499>. 

A bicyclic urea (123) was an unexpected product of the reaction between pyrrolidine and the phenyl ester of 2-cyano-l,4,5,6-tetrahydro-l-pyridinecarboxylic acid (124 R = Ph) the corresponding methyl ester (124 R = Me) reacted, as expected, to give the product of Michael addition (125). ° The better leaving ability of phenoxide vs methoxide presumably tilted the reaction towards the substitution rather than the addition product, although thiols (e.g. PhSH) underwent only the addition reaction. 

Oxidation of methylpyridines in 60-80 % sulphuric acid at a lead dioxide anode leads to the pyridinecarboxylic acid [213]. The sulphuric acid concentration is critical and little of the product is formed in dilute sulphuric acid [214]. In these reactions, electron loss from the n-system is driven by concerted cleavage of a carbon-hydrogen bond in the methyl substituent. This leaves a pyridylmethyl radical, which is then further oxidised to the acid, fhe procedure is run on a technical scale in a divided cell to give the pyridinecarboxylic acid in 80 % yields [215]. Oxida-tionof quinoline under the same conditions leads to pyridine-2,3-dicarboxylic acid [214, 216]. 3-HaIoquino ines afford the 5-halopyridine-2,3-dicarboxylic acid [217]. Quinoxaline is converted to pyrazine-2,3-dicarboxylic acid by oxidation at a copper anode in aqueous sodium hydroxide containing potassium permanganate [218]. 

Lutidme (2,3-dimethylpyndine) is the starting material for the herbicide 2-[4,5-dihydro-4-methyl-4-(l-methylethyl)-5-oxo-lH-imidazol-2-yl]-3-pyridinecarboxylate (compound with 2-propanaminei, tradenamed Arsenal. 1... 

Spanish workers have recently described a rapid method for the construction of pyridoacridines which could be of value for the synthesis of a range of cytotoxic pyridoacridine alkaloids. Thus, treatment of MEM-protected 4-quinolone 1 with 3 equivalents of LDA in THF, first at -78°C then with stirring at room temperature, followed by addition of 1 equivalent of methyl 3-formyl-2-pyridinecarboxylate gave, after quench with aqueous ammonium chloride and chromatography, a mixture of the tetracycles 2 (15%) and 3 (20%). Oxidation of either 2 or 3, or a mixture of 2... 

Acetonyl-3-pyridinecarboxylic acid (75) gave 7-methyl-1,6-naphthyridin-5(6Z/)-one (76) (NH4OH, reflux, 18 h 80% analogs likewise).1072... 

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