Results 201 to 210 of about 17,511 (250)

Novel regioselective hydroxylations of pyridine carboxylic acids at position C2 and pyrazine carboxylic acids at position C3

Applied Microbiology and Biotechnology, 2000
We have previously described the isolation of the new bacterial species, Ralstonia/Burkholderia sp. strain DSM 6920, which grows with 6-methylnicotinate and regioselectively hydroxylates this substrate in the C2 position by the action of 6-methylnicotinate-2-oxidoreductase to yield 2-hydroxy-6-methylnicotinate (Tinschert et al. 1997).
A, Tinschert, A, Tschech, K, Heinzmann, A, Kiener   +3 more
openaire   +2 more sources

Kinetics of the Reactions of Pyridine and Pyridine-N-oxide Carboxylic Acids and Substituted Benzoic Acids with Diazodiphenylmethane in Various Alcohols

Journal of Chemical Research, 1998
Solvent effects on the reactivity of pyridine and pyridine-N-oxide carboxylic acids and p-substituted benzoic acids in their reaction with diazodiphenylmethane (DDM) in alcohols have been investigated and the rate constants interpreted by Hammett parameters using multiple regression analysis; the influence of solvents on the reactivity of these acids ...
Jovanović, Bratislav Ž., Drmanić, Saša, Misić-Vuković, Milica   +2 more
openaire   +2 more sources

The Paper-Chromatography of the Pyridine- and Piperidine-Carboxylic Acids

Journal of Experimental Botany, 1955
SUMMARY The Rp values in three conditions, and measured under carefully controlled conditions, are given in these solvent systems for pyridine 2-, 3-, and 4-carboxylic acids and for piperidine 2-, 3-, and 4-carboxylic acids. Certain anomalies in these Rp values are discussed.
openaire   +1 more source

Silver complexes of pyridine carboxylic acids and of 8-hydroxyquinoline

Journal of Inorganic and Nuclear Chemistry, 1974
Abstract The 8-hydroxyquinoline and pyridine carboxylic acid complexes of silver have been reinvestigated using ESCA, i.r. and u.v. spectroscopy, and through chemical properties in some cases. Many of the complexes do not have the simple 1:1 or 1:2 metal-ligand ratios previously assigned.
A.D. Baker, Marion Brisk, A. Storch
openaire   +1 more source

Amphoteric ion-exchangers based on pyridine carboxylic acids

Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, 1970
Amphoteric ion-exchangers have been prepared by the reaction of styrene and divinylbenzene copolymers of conventional and macroporous structure with pyridine carboxylic acids.
E. E. Ergozhin, B. A. Zhubanov, S. R. Rafikov, M. Kurmanaliev   +3 more
openaire   +1 more source

Separation of Pyridine Mono-Carboxylic Acids on Paper Chromatograms

Nature, 1956
CHEMICAL methods using cyanogen bromide and aromatic amines1–3 (Konig reaction) and an acid-indicator4 for the detection of pyridine carboxylic acids on paper chromatograms have been reported. But the toxic character of cyanogen bromide causes difficulty; and it has been observed that good spots with acid-indicator are often not produced, particularly ...
JIBAN K. CHAKRABARTI, AJOY K. GUHA
openaire   +1 more source

Infrared studies of carboxylic acids and pyridine in chloroform and methanol

Canadian Journal of Chemistry, 1978
The reactions of acetic, chloroacetic, and trichloroacetic acids with varying relative concentrations of pyridine in chloroform have been reinvestigated using infrared spectroscopy. The same Systems have also been studied in methanol. Some different assignments of peaks have been made, and the anomalous infrared results previously observed for ...
B. A. Dawa, Joan A. Gowland
openaire   +1 more source

The induced Raman spectrum of pyridine in solution in carboxylic acids

Soviet Physics Journal, 1976
Induced Raman scattering has been examined for pyridine in solution in formic and acetic acids; intermolecular hydrogen bonds affect the spectrum considerably.
N. I. Rezaev, M. B. Tabibi
openaire   +1 more source

2‐carbaldoximes of pyridine‐4‐ and 5‐carboxylic acids

Journal of Heterocyclic Chemistry, 1995
AbstractA series of pyridine‐2‐carbaldoximes, all of which are substituted at the 4‐ or 5‐position with derivatives of the corresponding carboxylic acids, have been prepared via the corresponding pyridine‐2‐carbaldehydes.
Hector Manuel Reyes‐Rivera, Robert O. Hutehins, David R. Dalton   +2 more
openaire   +1 more source

Carboxylic acid–pyridine supramolecular heterocatemer in a co-crystal

Journal of Molecular Structure, 2008
Abstract Robustness of carboxylic acid–pyridine supramolecular heterosynthon was examined in three 1:2 binary co-crystals of 4,4′-bipyridine with monocarboxylic acids, (4,4′-bipyridine)·( dl -hydroxyphenylacetic acid)2, 1; (4,4′-bipyridine)0.5·(4-bromonaphthalene-1-carboxylic acid), 2 and (4,4′-bipyridine)0.5·(4-methylbenzoic acid), 3.
P. Sudhakar, R. Srivijaya, B.R. Sreekanth, P.K. Jayanthi, Peddy Vishweshwar, Moses J. Babu, K. Vyas, Javed Iqbal   +7 more
openaire   +1 more source