- Two series of reactant's ratio-dependent lanthanide organic frameworks derived from nicotinic acid N-oxide and oxalate: Synthesis, crystal structures and luminescence properties
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Two series of lanthanide(iii)-organic frameworks with the molecular formula [Ln2(NNO)2(OX)2(H2O)4]n (Ln = Eu 1, Tb 2, Sm 3, Dy 4, Gd 5) and [Ln2(NNO)4(OX)(H2O)2]n (Ln = Eu 6, Tb 7, Sm 8, Dy 9, Gd 10) were synthesized successfully under the same hydrothermal conditions with nicotinic N-oxide (HNNO) and oxalic acid (H2OX) as the mixed ligands merely through varying the molar ratio of the reactants. The compounds were characterized by IR, elemental analysis, UV, TG-DTA and powder X-ray diffraction (XRD). X-ray single-crystal diffraction analyses of compounds 1 and 7 selected as representatives and powder XRD analysis of the compounds revealed that both the series of compounds feature three-dimensional (3-D) open frameworks, and crystallize in the triclinic P1 space group while with different unit cell parameters. In compound 1, pairs of Eu3+ ions and pairs of NNO- ligands connect with each other alternately to form a 1-D infinite Eu-NNO double chain, the adjacent 1-D double-chains are then joined together through OX2- ligands leading to a 2D layer, the 2-D layers are further 'pillared' by OX2- ligands resulting in a 3-D framework. In compound 7, the 1-D Tb-NNO infinite chain and its 2-D layer are formed in an almost similar fashion to that in compound 1. The difference between the structures of the two compounds 1 and 7 is that the adjacent 2-D layers in compound 7 are further connected by NNO- ligands resulting in a 3-D framework. The photoluminescence properties and energy transfer mechanism of the compounds were studied systematically. The energy level of the lowest triplet states of the HNNO ligand (23148 cm-1) was determined based on the phosphorescence spectrum of compound 5 at 77 K. The 5D0 (Eu3+) and 5D4 (Tb3+) emission lifetimes are 0.46 ms, 0.83 ms, 0.69 ms and 0.89 ms and overall quantum yields are 1.03%, 3.29%, 2.58% and 3.78% for the compounds 1, 2, 6 and 7, respectively. This journal is
- Yu, Yanyan,Zhang, Lijuan,Zhou, Yunshan,Zuhra, Zareen
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- REINVESTIGATION OF THE REACTION OF NICOTINIC ACID 1-OXIDE WITH ACETIC ANHYDRIDE
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Reinvestigation of the reaction of nicotinic acid 1-oxide (1) with boiling acetic anhydride has revealed that the primary product is not 2-acetylnicotinic acid 1-oxide (3) but 3-acetoxy-4-aza-3-methyl-1(3H)-isobenzofuranone 4-oxide (2), the acetate of the ring tautomer of 3.Reactions of 2 and 3 with phosphorus trichloride and some related reactions are reported.
- Nagano, Hiroyuki,Hamana, Masatomo,Nawata, Yoshiharu,Prachayasittikul, Supaluk,Abdel-Sayed, Ashraf N.,Bauer, Ludwig
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- Recyclable anhydride catalyst for H2O2 oxidation:: N -oxidation of pyridine derivatives
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The catalytic efficiency and recyclability of poly(maleic anhydride-alt-1-octadecene) (Od-MA) and poly(maleic anhydride-alt-1-isobutylene) (Bu-MA) were evaluated for use in the development of a metal-free, reusable catalyst for the oxidation of pyridines to pyridine N-oxides in the presence of H2O2. The Od-MA catalyst was easily recovered via filtration with recovery yields exceeding 99.8%. The catalyst retained its activity after multiple uses and did not require any treatment for reuse. The Od-MA and H2O2 catalytic system described herein is eco-friendly, operationally simple, and cost-effective; thus, it is industrially applicable. Od-MA and H2O2 could potentially be used in place of percarboxylic acid as an oxidant in a wide range of oxidation reactions.
- Gajeles, Ghellyn,Kim, Se Mi,Lee, Kyung-Koo,Lee, Sang Hee,Yoo, Jong-Cheol
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p. 9165 - 9171
(2020/03/13)
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- Ligand-regulated assemblies of three 1D to 3D Cu(II) coordination polymers: Structural diversities and magnetic properties
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Three structurally diverse Cu(II) coordination polymers (CPs) from one-dimension (1D) to three-dimension (3D) upon nicotinate N-oxide (NNO) and isonicotinate N-oxide (INO) ligands have been synthesized solvothermally. CP 1 [Cu3(NNO)4(OH)2(H2O)2]n based on NNO ligand displays a 1D wavy double-chain. CP 2 [Cu(INO)(OH)]n based on INO ligand possesses a 2D wavy double-sheet. CP 3 [Cu(INO)(CH3O)]n based on INO ligand exhibits a 3D framework with 1D wavy channels. Structural comparisons indicate that the position of functional group of ligand, the coordination modes of ligand, the solvent system determine these diversified CPs. And Moreover, the structural diversity of CPs 1–3 further result in their different magnetic behaviors.
- Cuo, Lei-Lei,Kang, Yi-Fan,Ma, Yang-Min,Wang, Yun-Luo,Xu, Li,Zhang, Wen-Qian
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- New green technology for preparation of 2-chloronicotinic acid
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The invention relates to a new green technology for preparation of 2-chloronicotinic acid. The technology includes: adopting nicotinic acid (I) as the raw material, conducting hydrogen peroxide N-oxidation under the action of a catalyst in a water system to obtain nicotinic acid N-oxide (II), then under the action of organic base, conducting phosphorus oxychloride chlorination to synthesize 2-chloronicotinyl chloride (III), and then performing hydrolysis and refining to obtain 2-chloronicotinic acid (IV). The method avoids the use of benzene and acetic acid, has the advantages of short process, safety and environmental protection, good product quality and high yield, is an environment-friendly green synthetic route, and is suitable for industrial production.
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Paragraph 0026; 0027; 0030; 0031
(2019/01/24)
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- The kinetics and mechanism for the oxidation of nicotinic acid by peroxomonosulfate in acidic aqueous medium
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The kinetics of oxidation of nicotinic acid by peroxomonosulfate (PMS) has been studied in acetate buffers. Stoichiometry of the reaction corresponds to the reaction of one mole of the oxidant with a mole of nicotinic acid. N→O product has been confirmed both by UV visible and IR spectroscopy. The reaction is second order viz. first order with respect to each reactant. Activation parameters have also been evaluated. A plausible reaction mechanism is mentioned and the derived kinetic rate law accounts for experimental observations.
- Agrawal, Anju,Sailani, Riya,Gupta, Beena,Khandelwal,Sharma
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experimental part
p. 212 - 216
(2012/06/15)
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- Organic salts of polyoxometalates: Novel and efficient catalysts for the synthesis of pyridine n-oxide derivatives
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Catalytic N-oxidation of pyridine derivatives to related N-oxides were performed in the peresence of three organic salts of polyoxometalates including two heteropolyanion (THA)7.7H6.3[NaP5W 30O110], 1, and (THPA)7.5 H 6.5[NaP5W30O110], 2, and one isopolyanion [TBA]2[W6O19] (3) with W as central metal atom. Catalyst (3) showed the best catalytic activity. The highly selective oxidation gave good to excellent yields of the related N-oxides along with decarboxylation at 2-position of pyridine ring. The effect of some operative variables, such as temperature, various solvents, and the reaction time was studied. The reaction conditions were optimized. Copyright Taylor & Francis Group, LLC.
- Tavakoli-Hoseini, Niloofar,Bamoharram, Fatemeh F.,Heravi, Majid M.
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experimental part
p. 912 - 915
(2011/02/28)
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- A chemoselective deoxygenation of N-oxides by sodium borohydride-Raney nickel in water
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A simple and convenient protocol for deoxygenation of aliphatic and aromatic N-oxides to the corresponding amines in good to excellent yield using sodium borohydride-Raney nickel in water is reported. Other functional moieties such as alkenes, halides, ethers, and amides are unaffected under the present reaction condition.
- Gowda, Narendra B.,Rao, Gopal Krishna,Ramakrishna, Ramesha A.
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supporting information; experimental part
p. 5690 - 5693
(2010/11/05)
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- Design of 3-D europium(iii)-organic frameworks based on pyridine carboxylate N-oxide and acyclic binary carboxylate: Syntheses, structures, and luminescence properties
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Four europium(iii) complexes of 3-D open frameworks [Eu2(NNO) 4(ox)(H2O)2]n (1), [Eu 2(INO)2(ox)2(H2O)2] n (2), {[Eu2(INO)2(suc)2]·2. 99H2O}n (3) and {[Eu2(suc)3(H 2O)2]·H2O}n (4) (HNNO = nicotinic acid N-oxide, H2ox = oxalic acid, HINO = isonicotinic acid, H2suc = succinic acid) have been synthesized and characterized by IR, elemental analysis, TG/DTA and single-crystal X-ray diffraction analysis. Each of the four complexes has 1-D channels, and in 3 and 4 these are filled with solvent water molecules, making them bigger than in 1 and 2, where no lattice water molecules can reside. The formation of the four 3-D europium(iii) frameworks of different molecular and crystal structures reflects the influence of the ligands' coordination modes, the length of the acyclic binary carboxylates, the ligand conformation as well as the molar ratio of reactants. At room temperature, all the complexes in the solid state exhibit typical red luminescence from Eu3+ ions, indicating effective energy transfer from the ligand to Eu3+ ion; however, their luminescence intensities are clearly different. The luminescence of 3 is the most intense due to the absence of coordinated water, while the complexes 1, 2 and 4 exhibit weaker luminescence due to oscillation of coordinated water molecules, which partially quenches their luminescence.
- Zhang, Lijuan,Xu, Donghua,Zhou, Yunshan,Jiang, Fei
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body text
p. 2470 - 2478
(2011/01/11)
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- Kinetics of oxidation of nicotinic and isonicotinic acids by permanganate in acidic medium
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The most important feature of this study of the oxidation of nicotinic acid (Nic) and isonicotinic acid (Inic) by permanganate in acidic medium is the complete solution of the rate laws (A) for Nic and (B) for Inic by varying [H+] over an extended concentration range. -d[MnO4 -]/dt = {k0 K1 [H+] + k K 1 K2 [H+]2 + k3 K 1 K2 K3 [H+]3}[MnO 4-]t[Nic]0 / {1 + K1 [H+] + K1 K2 [H+]2} (A) -d[MnO4-]/dt = {k K2 [H+] + k 3 K2 K3 [H+]2} [MnO 4-]t[Inic]/{1 + K2 [H+]} (B) The relationships of the rate parameters and their values are as follows : K1 (NC5H4COO- + H+ ? HN+C5H4COO- [B]), 1.78 × 104 (30°) (Nic); K2 (HN+C 5H4COO- [B] + H+ ? HN +C5H4COOH [C]), 46.2 (30°) (Nic), 33.6 (40°) (Inic); k0 ([B] + MnO4- → products), 1.56 × 10-3 L mol-1 s-1 (30°) (Nic); k ([C] + MnO4- → products), 1.64 × 10-2 (30°) (Nic), 1.68 × 10-3 L mol -1 s-1 (40°) (Inic) and k3 K3 ([C] + HMnO4 → products), 2.02 × 10-2 (30°) (Nic), 3.2 × 10-3 L2 mol-2 s -1 (40°) (Inic). The reactivity of Nie was greater than that of Inic.
- Sharma, Ashok,Sharma, Anil K.,Gupta
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experimental part
p. 649 - 653
(2010/07/05)
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- Facile, one-step production of niacin (vitamin B3) and other nitrogen-containing pharmaceutical chemicals with a single-site heterogeneous catalyst
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Niacin (3-picolinic acid), which is extensively used as vitamin B 3 in foodstuffs and as a cholesterol-lowering agent, along with other oxygenated products of the picolines, 4-methylquinoline, and a variety of pyrimidines and pyridazines, may be produced in a single-step, environmentally benign fashion by combining single-site, open-structure, heterogeneous catalysts witha solid source of active oxygen, namely acetyl peroxyborate (APB), in the absence of an organic solvent. The high activities, selectivities, and the relatively mild conditions employed with this single-site heterogeneous catalyst, coupled with ease of transport, storage, and stability of the solid oxidant, augurs well for the future use of APB in conjunction with other open-structure, single-site catalysts for fine-chemical, pharmaceutical, and agrochemical applications.
- Raja, Robert,Thomas, John Meurig,Greenhill-Hooper, Michael,Ley, Steven V.,Almeida Paz, Filipe A.
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experimental part
p. 2340 - 2348
(2009/04/11)
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- The crystal structures of
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The new heteropolyperoxometalate compounds [NMe4][(Me2AsO2){MoO(O2) 2}2] 1, [NMe4][(Ph2PO2){MoO(O2) 2}2] 2, [NBun4][(Ph2PO2){WO(O 2)2}2] 3 and [NH4][(Ph2PO2){MoO(O2) 2(H2O)}] 4 have been isolated and their crystal structures determined. Compounds 1-3 are dinuclear, whilst compound 4 is mononuclear; in all four structures the metal centre(s) have essentially identical pentagonal-bipyramidal co-ordination geometries with a weak axial ligand trans to an oxo group. The utility of 3 as a catalyst for the oxidation of alkenes, alcohols and tertiary amines with hydrogen peroxide as cooxidant has been studied.
- Gresley, N. Melanie,Griffith, William P.,Parkin, Bernardeta C.,White, Andrew J. P.,Williams, David J.
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p. 2039 - 2045
(2007/10/03)
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- AN IMPROVED PROCEDURE FOR THE PREPARATION OF AROMATIC HETEROCYCLIC N-OXIDES
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An improved procedure for the preparation of aromatic heterocyclic N-oxide is described.Nitrogen containing heterocyclic compounds gave their N-oxides in excellent yields by the reaction of m-CPBA in DMF/MeOH in the presence of HF in a short time under mild reaction conditions.The presence of HF and MeOH is crucial for the reaction.
- Rhie, Soo Young,Ryu, Eung K.
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p. 323 - 328
(2007/10/03)
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- Heteropolyperoxo- and Isopolyperoxo-tungstates and -molybdates as Catalysts for the Oxidation of Tertiary Amines, Alkenes and Alcohols
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The catalytic oxidation of tertiary amines to the corresponding N-oxides by 4>(3-) (X = P or As, M = Mo or W) and by (2-) with H2O2 as co-oxidant has been studied.Epoxidation of alkenes and oxidation of alcohols by (2-) with H2O2 as co-oxidant has also been examined and compared with that effected by 4>(3-).A possible structure for (2-) is suggested.
- Bailey, Alan J.,Griffith, William P.,Parkin, Bernardeta C.
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p. 1833 - 1838
(2007/10/02)
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- FURTHER FUNCTIONAL GROUP OXIDATIONS USING SODIUM PERBORATE
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Sodium perborate in acetic acid is an effective reagent for the oxidation of aromatic aldehydes to carboxylic acids, iodoarenes to (diacetoxyiodo)arenes, azines to N-oxides, and various types of sulfur heterocycles to S,S-dioxides.Nitriles are unaffected by the reagent in acetic acid, but undergo smooth hydration to amides when aqueous methanol is employed as solvent.
- McKillop, Alexander,Kemp, Duncan
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p. 3299 - 3306
(2007/10/02)
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- The Mechanism of the Reaction of Nicotinic Acid 1-Oxide with Acetic Anhydride
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In order to elucidate the mechanism of the 2-acetylation in the reaction of nicotinic acid 1-oxide (2a) with boiling acetic anhydride, thermal reactions and reactions with hot acetic anhydride have been explored with 3-X-pyridine 1-oxides (2).The former reactions of 2d (X = CONHAc), 2f (X = CONMeAc), 2h (X = CH2OAc) and 2j result in recovery or decomposition.The latter reactions of 2c (X = CONH2), 2d, 2e (X = CONHMe), 2h and 2j bring about mainly deoxygenative α-acetoxylation, no 2-acetylation being noticed.However, the reaction of 2f with acetic anhydride affords 6,7-dihydro-6-methyl-7-methylene-5H-pyrrolopyridin-5-one 1-oxide (7) as an initial product, which further undergoes deoxygenative β-acetoxylation to give 7-acetoxy-7-acetoxymethyl-6,7-dihydro-6-methyl-5H-pyrrolopyridin-5-one (8) and 7-acetoxymethylene-6,7-dihydro-6-methyl-5H-pyrrolopyridin-5-one (9).On the basis of the results we propose a new electrophilic pathway for the 2-acetylation of 2a and 2f.Keywords - pyridine 1-oxide 3-substituted; nicotinic acid 1-oxide; nicotinamide 1-oxide N-acetyl-N-methyl; pyrrolopyridine; 2-acetylation; pyridone formation
- Nagano, Hiroyuki,Nawata, Yoshiharu,Hamana, Masatomo
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p. 4068 - 4077
(2007/10/02)
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- Heterocyclic Analogues of Phthalhydrazides: Cyclic Hydrazides of Pyridine 1-Oxide and Pyrazine 1,4-Dioxide Dicarboxylic Acids
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The synthesis of N-oxides of the cyclic hydrazides of pyridine and pyrazine o-dicarboxylic acids is described.Pyridopyridazine-5,8-dione 1-oxide, pyridopyridazine-1,4-dione 6-oxide, and pyrazinopyridazine-5,8-dione 1,2-dioxide, were obtained by direct oxidation of the parent hydrazides with peracetic acid.The pyridopyridazine derivatives were also unambiguously synthesized by treating the anhydrides or diesters of the relevant carboxylic acid 1-oxides with hydrazine hydrate.
- Paul, D. Brenton
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- On derivatives of 4-oxo-3,4-dihydropyrido[2,3-d]pyrimidine (author's transl)
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A typical representative of the hypnotic and anticonvulsive 4-quinazoline group is methaqualone (1). A number of new derivatives of 4-oxo-3,4-dihydropyrido[2,3-d]pyrimidine (10) were synthetized by substituting the benzene ring in the quinazolone molecule by the pyridine ring. The synthesis was achieved by the condensation of 2-acetaminonicotinic acid (9) and a primary amine or by the reaction of 2-aminonicotinic acid (8) with acetic acid and a primary amine. These new compounds were tested on animals for antiphlogistic, analgetic and antipyretic activities and for effects on the central nervous system as well. It was tried to establish, on the basis of the results obtained, relations between the chemical constitution and the pharmacological efficacy. It was found that, depending on the nature of the substituents in the position 3; either the antiphlogistic, analgetic and antipyretic effects or the anticonvulsive action will prevail.
- Kretzschmar
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p. 253 - 256
(2007/10/02)
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