- Phototransformation of metoxuron [3-(3-chloro-4-methoxyphenyl)-1,1-dimethylurea] in aqueous solution
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UV irradiation of metoxuron in aerated aqueous solution at 254nm or between 300 and 450 nm led initially to an almost specific photohydrolysis of the C-C1 bond, resulting in the formation of 3-(3-hydroxy-4-methoxyphenyl)-1,1-dimethylurea (MX3) and hydroge
- Boulkamh, Abdelaziz,Harakat, Dominique,Sehili, Tahar,Boule, Pierre
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- By-products formation during degradation of isoproturon in aqueous solution. I: ozonation
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The degradation of the herbicide isoproturon during its ozonation in aqueous solution has been investigated with the aim of identifying intermediate as well as final by-products formed. At ambient temperature, phosphate-buffered (pH=7) isoproturon aqueous solutions (10, 10-1 and 10-3mg/l) were ozonated in a semi-batch reactor, under a continuous flow of ozonated air whose ozone concentration was 9 and 0.9mgO3/lair for the highest and the two lower herbicide concentrations respectively. Measured steady-state ozone concentrations during the two sets of experiments (i.e. the highest and the lower isoproturon concentration) were 1.9 and 0.7mgO3/l. Under all of the above conditions, isoproturon was always completely removed in a period ranging between 5 and 15min, essentially by reacting with molecular ozone. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analyses indicate that primary degradation by-products are formed either by introducing OH groups in the aromatic ring and/or in the side-chain substituents, or by breaking down the isopropyl alkyl chain. The results also show that these primary intermediates are successively degraded yielding low molecular weight compounds such as aldehydes, simple organic acids and α-oxo-acids, which have been identified by gas chromatography-electron capture detection (GC-ECD), ion chromatography (IC) and GC-MS, respectively. On the basis of the analytical results, a pathway for the degradation of isoproturon by ozone has been proposed. Copyright
- Mascolo, Giuseppe,Lopez, Antonio,James, Huw,Fielding, Mike
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- HARDENER AND CURE ACCELERANT WITH FLAME RETARDANCY EFFECT FOR CURING EPOXY RESINS (II)
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The present invention relates to novel hardeners for curing epoxy resins and to cure accelerants for the accelerated curing of epoxy resins comprising, in each case, at least one compound from the group of esters of phosphorus-containing acids according to Formula (I), wherein there applies to Formula (I): wherein there applies to the radicals R1, R2, R3, R6, X and indices m, n, p, simultaneously or independently of one another: R1, R2=simultaneously or independently of one another, hydrogen or alkyl, R3=alkyl, aryl, —O-alkyl, —O-aryl, —O-alkylaryl or —O-arylalkyl,R6=hydrogen, alkyl or —NHC(O)NR1R2,X=oxygen or sulphur,m=1, 2 or 3,n=0, 1 or 2, wherein there applies: m+n=3p=0, 1 or 2.
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Paragraph 0300-0304
(2018/04/26)
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- Kinetic and analytical study of the photo-induced degradation of monuron by nitrates and nitrites under irradiation or in the dark
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The photo-induced transformation of monuron (3-(4-chlorophenyl)-1,1 dimethylurea) was investigated in an aqueous solution containing nitrates and nitrites at 310 nm and 365 nm, respectively. In both NO3- and NO2-/sup
- Boucheloukh, Hadjira,Sehili, Tahar,Kouachi, Nadia,Djebbar, Kamel
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experimental part
p. 1339 - 1345
(2012/09/25)
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- Identification and formation pathway of laccase-mediated oxidation products formed from hydroxyphenylureas
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Hydroxyphenylureas are the first main metabolites formed in the environment from pesticide and biocide urea compounds. Because fungi release potent exocellular oxidases, we studied the ability of laccases produced by the white rot fungus, T. versicolor, to catalyze in vitro the transformation of five hydroxyphenylureas, to identify transformation pathways and mechanisms. Our results establish that the pH of the reaction has a strong influence on both the kinetics of the reaction and the nature of the transformation products. Structural characterization by spectroscopic methods (NMR, mass spectrometry) of eleven transformation products shows that laccase oxidizes the substrates to quinones or to polyaromatic oligomers. Slightly acidic conditions favor the formation of quinones as final transformation products. In contrast, at pH 5-6, the quinones further react with the remaining substrate in solution to give hetero-oligomers via carbon-carbon or carbon-oxygen bond formation. A reaction pathway is proposed for each of the identified products. These results demonstrate that fungal laccases could assist the transformation of hydroxyphenylureas.
- Jolivalt,Neuville,Boyer,Kerhoas,Mougin
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p. 5046 - 5054
(2007/10/03)
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- Transformation of fenuron induced by photochemical excitation of humic acids
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When neutral solutions containing the herbicide 3-phenyl-1,1-dimethylurea (fenuron) and-a humic acid are irradiated at 365 nm, 3-(4-hydroxyphenyl)-1,1-dimethylurea and three biphenyl products are formed as main products. The apparent quantum yield of fenuron disappearance is evaluated as 6-2 x KT'moleE-1. Upon irradiation of the same mixture at 253-7 nm, both direct and induced phototransformations of fenuron occur. Direct photooxidation yields 2- and 4amino-N,AT-dimethylbenzamide. The induced phototransformation leads to 2and 4-hydroxylation of the aromatic ring in accordance with the fact that hydroxyl radicals are involved in the oxidation.
- Aguer, Jean-Pierre
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p. 151 - 155
(2007/10/03)
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- 1-Methoxy-1-methyl-3-{p-[(1,1-dimethyl-2-propynyloxy)-methoxy]phenyl}urea
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This invention relates to novel (alkenyloxy), (alkynyloxy) and (cyanoalkoxy) alkoxyphenyl ureas and their use as herbicidal agents.
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- New amines and processes for their manufacture
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Compounds selected from the group consisting of amines of the formula I EQU1 in which R1 and R2 stand for a member selected from lower alkyl, lower alkenyl, cycloalkyl having 4 to 7 ring members, phenyl-lower alkyl, phenyl-lower alky
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