The chemistry of heterocycles. IV. 2<i>H</i>‐pyrido[4,3‐e]‐1,3‐oxazine‐2,4(3<i>H</i>)‐dione, its precursors and some 3‐substituted derivatives.

Crum, J. D.; Fuchsman, Charles H.

doi:10.1002/jhet.5570030302

Cited by 20 publications

(4 citation statements)

References 20 publications

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“…For the synthesis of l(N)-(2,6-dichlorobenzyl)-2-aminomethyl-l,4-dihydronicotinic acid lactame (IV), 8hvdroxvauinoline was oxidized with nitric acid to Dvridine-2:3-dickboxylic acid. This, after condensat& with ammonia to the corresponding imine, was selectively reduced with ZniHCl to 2-aminomethyl nicotinic acid lactame (Crum and Fuchsman, 1966;Dobeneck and Hansen, 1972), and subsequently N( 1)-substituted and reduced as described above. Satisfactory elemental analyses were obtained for all four compounds I-IV.…”

Section: Methodsmentioning

confidence: 99%

Spectroscopic Investigation of Dihydronicotinamides‐i: Conformation, Absorption, and Fluorescence

Fischer

Fleckenstein

Hönes

1988

Photochem & Photobiology

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The 1(N)-(2,6-dichlorobenzyl)-I,4-dihydronicotinamide (I). N-methyl-and N,N-dimethyl-1(N)-(2,6-dichlorobenzyl)-l,4-dihydronicotinamide (I1 and III), respectively). and l(N)-(2,6-dichlorobenzyl)-2-aminomethy1-1,4-dihydronicotinic acid lactame (IV) were synthesized as model compounds for natural coenzymes, and systematically studied by 'H NMR, UViVlS absorption and fluorescence spectroscopy. The absorption at -340 nm argues for an effective conjugation between dihydropyridine and carboxamide 7r-system, and rules out any severely twisted conformation. For the natural coenzymes NADH and NMNH, as well as for I and I1 (with no or only one N-arnide substituent), IH NMR definitively establishes a transoid conformation in solution, with the carbonyl 0 close to 2-H of the dihydropyridine ring. N,N-dimethyl substitution effectively inverts the carboxamide orientation into the cisoid form. The 'H NMR data (as well as molar extinctions) for the fused-ring derivatives IV and V, with a fixed cisoid and transoid structure, respectively, provide final proof for the conformational assignment.Absorption maxima are shifted to lower energies with increasing solvent polarity. In solvents which can act as hydrogen bond acceptors to the carboxamide N-H, absorption shows a general blue-shift of -10 nm. H-bond donor solvents do not affect absorption maxima but enhance molar extinction.Fluorescence maxima show a similar dependence on solvent polarity but no specific hydrogen-bonding effect. Fluorescence quantum yields appear increased tenfold in solvents donating H-bonds to the carboxamide C=O group. These results are interpreted in terms of the vinylogous amide resonance between C = O function and ring-N lone pair being the electronic interaction dominating in the ground state of dihydronicotinamides.

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Section: Methodsmentioning

confidence: 99%

Spectroscopic Investigation of Dihydronicotinamides‐i: Conformation, Absorption, and Fluorescence

Fischer

Fleckenstein

Hönes

1988

Photochem & Photobiology

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“…In a flask equipped with a condenser and a water separator, a mixture of 3-hydroxyisonicotinic acid [3] (30 g, 0.216 mole), ethanol (550 ml), benzene (180 ml) and 98% sulfuric acid (9 ml) wa5 refluxed for 48 hours. After evaporation of the excess ethanol and benzene in uacuo, the slightly yellow syrup was dissolved in 700 ml of water, neutralized with sodium bicarbonate, extracted with chloroform and dried over magnesium sulfate.…”

Section: Ethyl 3-hydroxyisonicotinate (2)mentioning

confidence: 99%

“…To start with, we prepared the hydroxy acid 1 by the method of Crum and Fuchsman [3]. Esterification of the acid 1 with ethanol by the conventional method yielded the ethyl ester (2) in good yield.…”

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confidence: 99%

Furopyridines. V. A simple synthesis of furo[2,3‐c]pyridine and its 2‐and 3‐methyl derivatives

Morita¹,

Shiotani²

1986

Journal of Heterocyclic Chem

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A simple synthesis of furo[2,3‐c]pyridine and its 2‐ and 3‐methyl derivatives from ethyl 3‐hydroxyisonicotinate (2) is described. The hydroxy ester 2 was O‐alkylated with ethyl bromoacetate or ethyl 2‐bromopropionate to give the diester 3a or 3b. Cyclization of compound 3a afforded ethyl 3‐hydroxyfuro [2,3‐c]pyridine‐2‐carboxylate (4) which was hydrolyzed and decarboxylated to give furo[2,3‐c]pyridin‐3(2H)‐one (5a). Cyclization of 3b gave the 2‐methyl derivative 5b. Reduction of 5a and 5b with sodium borohydride yielded the corresponding hydroxy derivative 6a and 6b, respectively, which were dehydrated with phosphoric acid to give furo[2,3‐c]pyridine (7a) and its 2‐methyl derivative 7b. 4‐Acetylpyridin‐3‐ol (8) was O‐alkylated with ethyl bromoacetate to give ethyl 2‐(4‐acetyl‐3‐pyridyloxy) acetate (9). Saponification of compound 9, and the subsequent intramolecular Perkin reaction gave 3‐methylfuro[2,3‐c]pyridine (10). Cyclization of 9 with sodium ethoxide gave 3‐methylfuro[2,3‐c]pyridine‐2‐carboxylic acid, which in turn was decarboxylated to give compound 10.

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“…N-Methyl-3-hydroxyisonicotinic acid (X) was synthesized in three steps. 3-Hydroxyisonicotinic acid was prepared from cinchomeronic (pyridine-3,4dicarboxylic) acid via 3-aminoisonicotinic acid, and the carboxyl group was then esterified with methanol and SOCI2 (Crum & FuchSMan, 1966). 3-Hydroxyisonicotinic acid methyl ester (0.3 g) was then mixed with 2-aminopyridine (0.183g) and heated to 150°C, then cooled rapidly before being left overnight.…”

Section: Chemical Synthesesmentioning

confidence: 99%

Microbial metabolism of pyridinium compounds. Metabolism of 4-carboxy-1-methylpyridinium chloride, a photolytic product of paraquat

Wright

Cain

1972

Biochemical Journal

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1. A bacterium, Achromobacter D, isolated from garden soil by elective culture, utilized N-methylisonicotinic acid (4-carboxy-1-methylpyridinium chloride) as sole carbon source. 2. Extracts of N-methylisonicotinate-grown cells oxidized this substrate only after supplementation with a source of nicotinamide nucleotides and then consumed 1 mol of O(2) and released 1 mol of CO(2)/mol of N-methylisonicotinate supplied. 3. The N-methyl group of the substrate was released as methylamine whereas the five C atoms of the pyridine ring were accounted for as succinate and formate. The CO(2) evolved by extracts was believed to derive from the carboxyl group on C-4 of the heterocyclic ring. 4. The immediate precursor of the succinate end-product was succinic semialdehyde; the inducible nature of succinic semialdehyde dehydrogenase in N-methylisonicotinate-grown cells supported this finding. 5. There was no evidence for monohydroxylation of the ring, but the time sequence of the appearance of the end-products indicated that the oxygen-requiring, NADH-requiring and decarboxylation steps clearly preceded the formation of methylamine and succinate. 6. The results are consistent with the oxidative cleavage of a partially reduced heterocyclic ring followed by several hydrolytic and dehydrogenase steps resulting in the appearance of the end-products.

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The chemistry of heterocycles. IV. 2H‐pyrido[4,3‐e]‐1,3‐oxazine‐2,4(3H)‐dione, its precursors and some 3‐substituted derivatives.

Cited by 20 publications

References 20 publications

Spectroscopic Investigation of Dihydronicotinamides‐i: Conformation, Absorption, and Fluorescence

Spectroscopic Investigation of Dihydronicotinamides‐i: Conformation, Absorption, and Fluorescence

Furopyridines. V. A simple synthesis of furo[2,3‐c]pyridine and its 2‐and 3‐methyl derivatives

Microbial metabolism of pyridinium compounds. Metabolism of 4-carboxy-1-methylpyridinium chloride, a photolytic product of paraquat

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