- Preparation method of nicosulfamide
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The invention relates to the technical field of pesticide synthesis, in particular to a preparation method of nicosulfamide. The preparation method of the smoke sulfonamide comprises the following steps: taking 3-cyanopyridine as a raw material, and carrying out oxidation reaction to obtain 3-cyanopyridine nitric oxide; carrying out sulfonation reaction and ammoniation reaction on the 3-cyanopyridine nitrogen oxide to obtain 2-sulfonamido-3-cyanopyridine; carrying out alkaline hydrolysis on the 2-sulfamido-3-cyanopyridine to obtain 2-sulfamido nicotinic acid; and carrying out amidation reaction on the nicotinic acid 2-sulfonamide to obtain the nicotinamide. The preparation method of the nicosulfamide is simple to operate and low in raw material cost, by-products generated in the preparation process can be recycled, the cost is saved, and the prepared nicosulfamide is high in yield and purity.
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Paragraph 0008; 0044-0046; 0055-0057; 0064-0066
(2021/03/13)
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- A pyridine nitrogen oxide high-efficient, multi-phase catalytic preparation method
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The invention discloses a high efficient heterogeneous catalytic preparation method of pyridine oxynitride. In the provided preparation method, mono-substituted or poly-substituted pyridines or pyridine derivatives are taken as the primary raw materials, titanium dioxide loaded on tungsten (WO3/TiO2) is taken as the catalyst, hydrogen peroxide is taken as the oxidizing agent, and reactions are carried out in a water solution at a room temperature so as to obtain the target product. Compared with the prior art, the preparation method has the following advantages: (1) the provided oxidation method, no acetic acid is used, and thus the requirements on equipment are greatly reduced; (2) a heterogeneous catalytic method is adopted to prepare pyridine oxynitride, the catalyst can be separated from the reaction system through simple filtration or centrifugation, and the operation is convenient; (3) titanium dioxide loaded on tungsten is taken as the catalyst, pyridine oxynitride is prepared by one step in a water solution at a room temperature, the reaction conditions are mild, and the pollution to the environment is little.
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Paragraph 0104; 0108; 0109; 0110
(2017/08/25)
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- A 3-cyano-pyridine N-oxide preparation method
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The invention provides a preparation method of 3-cyano-pyridine N-oxide. The preparation method comprises the following steps that 3-cyano-pyridine is put into a reaction bottle; 3-cyano-pyridine is heated in the presence of water as a solvent and sulfuric acid as a co-catalyst; then an oxidizing agent is dropwisely added into the reaction bottle; the mixture undergoes an oxidation reaction; the reaction product is cooled, stood and filtered; and the filter residues are dried. The preparation method realizes high-selectivity and high-efficiency preparation of the 3-cyano-pyridine N-oxide. The 3-cyano-pyridine N-oxide has low nicotinamido-N-oxide content so that a follow-up chlorination reaction is promoted and a 2-chloronicotinic acid synthesis yield is improved. The preparation method has a low cost, improves the oxidation product purity and yield and is suitable for industrial production.
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Paragraph 0009; 0015; 0016
(2017/02/24)
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- Solvent- and halide-free synthesis of pyridine-2-yl substituted ureas through facile C-H functionalization of pyridine: N -oxides
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A novel solvent- and halide-free atom-economical synthesis of practically useful pyridine-2-yl substituted ureas utilizes easily accessible or commercially available pyridine N-oxides (PyO) and dialkylcyanamides. The observed C-H functionalization of PyO is suitable for the good-to-high yielding synthesis of a wide range of pyridine-2-yl substituted ureas featuring electron donating and electron withdrawing, sensitive, or even fugitive functional groups at any position of the pyridine ring (63-92%; 19 examples). In the cases of 3-substituted PyO, the C-H functionalization occurs regioselectively providing a route for facile generation of ureas bearing a 5-substituted pyridine-2-yl moiety.
- Rassadin, Valentin A.,Zimin, Dmitry P.,Raskil'dina, Gulnara Z.,Ivanov, Alexander Yu.,Boyarskiy, Vadim P.,Zlotskii, Semen S.,Kukushkin, Vadim Yu.
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supporting information
p. 6630 - 6636
(2018/03/01)
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- Renewable waste rice husk grafted oxo-vanadium catalyst for oxidation of tertiary amines to N-oxides
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Low cost renewable waste rice husks (RH) have been used as a support for grafting of an oxo-vanadium Schiff base via covalent attachment for the oxidation of tertiary amines to N-oxide. The synthesis of the desired RH grafted oxo-vanadium complex involves prior functionalization of the RH support with amino-propyltrimethoxysilane (APTMS) followed by its reaction with salicylaldehyde to get an RH-functionalized Schiff base which subsequently reacted with vanadyl sulphate to get the targeted oxo-vanadium catalyst. The synthesized catalyst was found to be an efficient heterogeneous catalyst and afforded an excellent yield of corresponding N-oxides via oxidation of tertiary amines with hydrogen peroxide as an oxidant. Furthermore, the synthesized catalyst was found to be quite stable and showed consistent activity for five runs without any loss in activity.
- Panwar, Vineeta,Bansal, Ankushi,Ray, Siddharth S.,Jain, Suman L.
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p. 71550 - 71556
(2016/08/05)
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- Silica-supported vanadium-catalyzed N-oxidation of tertiary amines with aqueous hydrogen peroxide
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A recyclable silica supported vanadium 1 catalyzes the oxidation of tertiray amines to the corresponding N-oxides with 30% H2O 2 in high yield.
- Rout, Laxmidhar,Punniyamurthy, Tharmalingam
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p. 1958 - 1960
(2007/10/03)
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- Pyridine-1-oxide derivative, and process for its transformation into pharmaceutically effective compounds
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The invention relates to N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine and its optically active enantiomers. (R)-(?)-N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine and (S)-(+)-N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxamidine. Furthermore, the invention relates to the preparation of N-[2-hydroxy-3-(1-piperidinyl)-propoxy]-pyridine-1-oxide-3-carboxyimidoyl chloride, which may be used as an active ingredient of medicaments, and the preparation of the optically active enantiomers of this compound using the compounds of the invention as intermediate substances.
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- Ruthenium catalyzed oxidation of tertiary nitrogen compounds with molecular oxygen: An easy access to N-oxides under mild conditions
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A variety of tertiary nitrogen compounds have been efficiently oxidized to their corresponding N-oxides in excellent yields with molecular oxygen as a sole oxidant and ruthenium trichloride as catalyst.
- Jain, Suman L.,Sain, Bir
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p. 1040 - 1041
(2007/10/03)
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- An efficient synthesis of heterocyclic N-oxides over molecular sieve catalyst
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Heterocyclic N-oxides have been synthesized in very high yields over redox molecular sieve catalysts in the presence of H2O2.
- Prasad, M. Ramakrishna,Kamalakar, G.,Madhavi, G.,Kulkarni, S. J.,Raghavan, K. V.
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p. 1577 - 1578
(2007/10/03)
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- A simple and efficient method for the preparation of pyridine-N-oxides II
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Oxidation of pyridines with bis(trimethylsilyl)peroxide in the presence of catalytic amounts of inorganic rhenium derivatives gives high yields of their analytically pure N-oxides by simple work-ups, typically a filtration or a Kugelrohr distillation.
- Coperet, Christophe,Adolfsson, Hans,Chiang, Jay P.,Yudin, Andrei K.,Sharpless, K. Barry
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p. 761 - 764
(2007/10/03)
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- Enthalpies of combustion of the pyridine N-oxide derivatives: 4-methyl-, 3-cyano-, 4-cyano-, 3-hydroxy-, 2-carboxy-, 4-carboxy-, and 3-methyl-4-nitro, and of the pyridine derivatives: 2-carboxy-, and 4-carboxy-. The dissociation enthalpies of the N-O bonds
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The standard (po = 0.1 MPa) molar enthalpies of formation ΔfHom(cr) at T = 298.15 K were determined using static-bomb calorimetry for crystalline 4-methylpyridine N-oxide (4MePyNO), 3-cyanopyridine N-oxide (3CNPyNO), 4-cyanopyridine N-oxide (4CNPyNO), 3-hydroxypyridine N-oxide (3OHPyNO), 2-pyridinecarboxylic acid N-oxide (2CO2HPyNO), 4-pyridinecarboxylic acid N-oxide (4CO2HPyNO), 3-methyl-4-nitropyridine N-oxide (3Me4NO2PyNO), 2-pyridinecarboxylic acid (2CO2HPy), and 4-pyridinecarboxylic acid (4CO2HPy). The standard molar enthalpies of sublimation ΔgcrHom at T = 298.15 K were measured by microcalorimetry, or by a mass-loss effusion technique, and from the enthalpies of formation of the gaseous compounds the dissociation enthalpies Dom of the (N+-O-) dative covalent bonds were derived. ΔfHom(cr)/(kJ · mol-1) ΔgcrHom/(kJ · mol-1) Dom(N-O)/(kJ · mol-1) 4-MePyNO 5.6 ± 2.1 85.3 ± 2.6 262.4 ± 3.4 3-CNPyNO 170.9 ± 1.4 101.9 ± 2.0 254.3 ± 3.1 4-CNPyNO 162.8 ± 1.4 104.4 ± 4.3 265.5 ± 4.6 3-OHPyNO -171.3 ± 1.0 121.8 ± 4.4 255.0 ± 4.8 2-CO2HPyNO -364.1 ± 1.8 94.4 ± 4.0 275.9 ± 5.1 4-CO2HPyNO -381.2 ± 1.3 136.1 ± 1.2 259.5 ± 5.0 3-Me4NO2PyNO -19.5 ± 3.4 106.7 ± 2.0 263.4 ± 7.1 2-CO2HPy -341.0 ± 1.2 98.0 ± 2.3 4-CO2HPy -348.7 ± 1.6 113.9 ± 4.4 Comparison has been made with Dom(N-O) values in pyridine N-oxide derivatives.
- Ribeiro da Silva, Maria D. M. C.,Agostinha,Matos,Vaz, M. Claudia,Santos, Luis M.N.B.F.,Pilcher,Acree Jr.,Powell, Joyce R.
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p. 869 - 878
(2007/10/03)
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- 2,4-diamino-5,6-disubstituted- and 5,6,7-trisubstituted 5-deazapteridines as insecticides
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An insecticidal composition comprising, in admixture with an agriculturally acceptable carrier, an insecticidally effective amount of a 5-deazapteridine compound of the formula: STR1 wherein R1, R2, R3, R4, U, V, and W are as defined herein; agriculturally acceptable salts thereof; methods for using the same; and certain novel 5-deazapteridines per se.
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- Pyrrolo 3,4-c!pyrroles containing amine oxide groups
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The invention relates to pyrrolo 3,4-c!pyrroles of formula STR1 wherein A and B are each independently of the other a group of formula STR2 or Q, wherein Q is a 5- or 6-membered heterocyclic aromatic amine oxide radical which is unsubstituted or substituted by one, two or three C1 -C18 alkyl, C1 -C18 alkoxy or STR3 and which may contain one or two fused benzene rings, R1 and R2 are each independently of the other hydrogen, halogen, C1 -C18 alkyl, C1 -C18 alkoxy, C1 -C18 alkylmercapto, --CN, --NO2 or trifiuoromethyl, D and E are each independently of the other hydrogen, C1 -C18 alkyl, C2 -C4 alkenyl, C7 -C10 aralkyl, unsubstituted phenyl or phenyl which is substituted by chloro, bromo, C1 -C6 alkyl, C1 -C4 alkoxy, trifiuoromethyl or nitro, with the proviso that at least one of the sustituents A and B is an amine oxide radical Q. These novel diketopyrrolo 3,4-c!pyrroles are suitable for use as pigments, but especially as photoconductive substances in electrophotographic photoreceptors.
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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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- KINETICS OF THE N OXIDATION OF SOME COMPOUNDS OF THE PYRIDINE SERIES WITH PERBENZOIC ACID IN CHLOROFORM AND AQUEOUS DIOXANE
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A comparative study of the kinetics of the N oxidation of 19 derivatives of the pyridine series with perbenzoic acid in choroform and aqueous dioxane at 20, 25, 30, and 35 deg C was made.The rate constants, the parameters of the Arrhenius equation, and the activation energies of the N oxidation of the indicated monoazines were determined.The scale of the reactivities of the derivatives of the pyridine series was calculated within the framework of the Pearson hard-soft acid-base concept.
- Lohkov, R.E.
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p. 264 - 271
(2007/10/02)
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