- PESTICIDALLY ACTIVE AZOLE-AMIDE COMPOUNDS
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Compounds of formula I wherein the substituents are as defined in claim 1, and the agrochemically acceptable salts, stereoisomers, enantiomers, tautomers and N-oxides of those compounds, can be used as insecticides.
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Page/Page column 70; 71
(2020/06/01)
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- HETEROARYL-1,2,4-TRIAZOLE AND HETEROARYL-TETRAZOLE COMPOUNDS FOR CONTROLLING ECTOPARASITES
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The present invention provides compounds of the formula : (I) wherein: X is O or S; Q1 and Q2 are independently CR5 or N, provided at least one of Q1 and Q2 is N; Y is a direct bond or CH2;
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Page/Page column 44
(2017/12/14)
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- Kinetics and mechanism of the cyclization of ω-(p-nitrophenyl)-hydantoic acid amides: Steric hindrance to proton transfer causes a 104-fold change in rate
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The pH-rate profiles for the cyclization of primary 2,3-dimethyl and 2,2,3-trimethyl-hydantoinamides (2-UAm and 3-UAm respectively) differ strikingly from those for the cyclizations of the corresponding N-methylated amides 2-MUAm and 3-MUAm; which are dominated by the water reaction, spanning some 6 pH units. For the cyclization of UAm the plateau extends over no more than two pH units. The difference is due to the slower base-catalyzed cyclization of the N-methylamides. The solvent kinetic isotope effect for this hydroxide-catalyzed reaction is close to 1.2, consistent with a slow protonation by water of the amino-group of the negatively charged tetrahedral intermediate. General base catalysis was observed with bases of pKBH up to 8. The Bronsted β are compatible with a hydrogen bonding mechanism for the GBC. In the gem-dimethyl compounds 3 the leaving group is flanked by substituents on both sides. The N-methyl group in 3-MUAm hinders frontal access of the proton, causing a 14000 fold decrease in rate. This is only 3800 fold in the compound with one methyl group at position 2.
- Angelova, Violina T.,Kirby, Anthony J.,Koedjikov, Asen H.,Pojarlieff, Ivan G.
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p. 859 - 865
(2007/10/03)
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- α-Aminonitrile hydration in the presence of hydrogen peroxide in aqueous basic medium
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α-Aminonitriles are hydrated into α-aminoamides in the presence of hydrogen peroxide in sodic or ammoniacal basic medium. While the hydration mechanism is close to the mechanism described previously in the case of aromatic nitrites, we showed that, in weakly basic conditions, the amine function of α-aminonitrile is competitively oxidized via a peroxyimidic acid by an intramolecular process. In the case of 2-aminopropanenitrile, this reaction leads to pyruvamide oxime. Furthermore, the study of structurereactivity relationships in the hydration of aliphatic and aromatic monofunctional nitriles and α-aminonitriles showed that the reactivity of the substrates towards hydroperoxide onion, which mostly depends on inductive effects of the substituents, is sufficiently enhanced to allow hydration of tertiary α-aminonitriles with low steric hindrance and regioselective hydration of dissymmetric α-aminodinitriles. Eisevier,.
- Taillades, Jacques
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- Mecanisme de la reaction de Bucherer-Bergs Comparaison avec l'hydratation basique des α-aminonitriles
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The Bucherer-Bergs reaction provides an important tool for the synthesis of α-aminoacids and is the basis of an industrial process for producing methionine.The key compound is the α-aminonitrile 1 which leads to partial decomposition in carbonate buffer as well as in weakly basic aqueous media and to the equilibrated formation of the basic intermediate α-carboxy-aminonitrile 2a.The parameters which control the stability of 2a are summarised.These equlibria are established through an initial fast step which is then followed by the formation of the hydantoin 5a.At a constant pH this formation is first order in α-carboxyaminonitrile 2a via a 5-imino-2-oxazolidinone 3a and an α-isocyanatamide 4a.A comparison of the reactivity of 1 with that of the N-alkylated compouds 7 shows that the rate determining step of the hydantoin formation is the cyclisation of 2a at pH9.But at higher pH, the reaction is controlled by the fast partitioning of the cyclic intermediate 3a between the α-carboxyaminonitrile 2a and the isocyanatamide 4a.This study permits the direct comparison between two mechanism for the synthesis of the racemic α-aminoacids: the Bucherer-Bergs way and the catalytic hydratation of α-aminonitriles.It is clear that carbonic anhydre can be considered as a special carbonyl compound with respect to its reactivity towards α-aminonitriles.
- Taillades, Jacques,Rousset, Alain,Lasperas, Monique,Commeyras, Auguste
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p. 650 - 658
(2007/10/02)
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- Interaction α-aminoamide - compose carbonyle. Mecanisme de formation des imidazolidinones-4
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The reaction of α-N-methylaminopropionamide 1 with formaldehyde was studied in unbuffered aqueous solution.The reaction led to 1,5-dimethyl-4 imidazolidinone, 2a, in equilibrium with 3-hydroxymethyl 1,5-dimethyl 4-imidazolidinone, 3a, formed by addition of a second formaldehyde molecule.A kinetic study of the formation of 2a and 3a indicated that the addition of the amino group of 1 was a complete equilibrium.The reaction pathway involved the rate determining attack of the amide group of 1 on formaldehyde to form a hydroxymethyl amide intermediate, which was not isolated.The intramolecular assistance by the amino group, noted for this step, was interpreted as an attack of 1 in a zwitterionic form.Secondary amines catalyzed the formation of 2a and 3a by a pathway which involved the intermediate formation of iminium ions >N=CH2(1+).
- Pascal, R.,Lasperas, M.,Taillades, J.,Commeyras, A.,Perez-Rubalcaba, A.
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p. 329 - 337
(2007/10/02)
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