- Preparation method of 2, 3, 5, 6-tetrachlorobenzoyl chloride
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The invention discloses a preparation method of 2, 3, 5, 6-tetrachlorobenzoyl chloride, and relates to the field of organic synthesis. The preparation method comprises the following steps of: synthesizing pentachlorobenzene serving as a raw material and m
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Paragraph 0040-0043; 0040; 0044; 0047-0054
(2020/10/04)
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- CARBOXYLATION CATALYSTS
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The use of a complex of the form Z—M—OR in the carboxylation of a substrate is described. The group Z is a two-electron donor ligand, M is a metal and OR is selected from the group consisting of OH, alkoxy and aryloxy. The substrate may be carboxylated at a C—H or N—H bond. The metal M may be copper, silver or gold. The two-electron donor ligand may be a phosphine, a carbene or a phosphite ligand. Also described are methods of manufacture of the complexes and methods for preparing isotopically labelled caboxylic acids and carboxylic acid derivatives.
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Paragraph 0093; 0095
(2013/04/13)
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- Carboxylation of C-H bonds using N -heterocyclic carbene gold(I) complexes
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A highly efficient [(NHC)AuI]-based (NHC = N-heterocyclic carbene) catalytic system for the carboxylation of aromatic and heteroaromatic C-H bonds was developed. The significant base strength of the Au-OH species is at the origin of the activation process and permits the facile functionalization of C-H bonds without the use of other organometallic reagents.
- Boogaerts, Ine I. F.,Nolan, Steven P.
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supporting information; experimental part
p. 8858 - 8859
(2010/08/21)
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- Process for the preparation of halogenated benzoic acids
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A process for the preparation of halogenated benzoic acids of formula (1): STR1 in which R1, R2, R3, R4 and R5 are hydrogen, fluorine, chlorine or bromine atoms or C1 -C6 -alkyl, C1 -C6 -alkoxy, nitro, cyano, trifluoromethyl, aidehyde, C1 -C4 -alkoxycarbonyl, -SO2 -C1 -C4 -alkyl, -SO2 -phenyl, -CONH2, -CON(C1 -C4 -alkyl)2, hydroxy, carboxy, -NH2 or -N(C1 -C4 - alkyl)2 groups, at least one of the substituents R1 -R5 being one of said halogen atoms, which comprises reacting 1 mol of a benzophenone, asymmetrically substituted on the benzene rings A and B, of general formula (2): STR2 in which R1 -R10 are as defined above for R1 -R5, with about 1 to about 10 mol of an oxidizing agent selected from the group comprising hydrogen peroxide, urea/hydrogen peroxide addition product, an alkali metal peroxide, ammonium, alkali metal or alkaline earth metal peroxodisulfates, pertungstates, perborates or percarbonates, ozone, alkyl- or aryl-percarboxylic acids, alkyl- or aryl-persulfonic acids or persulfuric acid, at temperatures from about -20° to about +100° C.
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- 5,6-Dihydro-1,2,4,6-thiatriazin-5-one-1,1-dioxides
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5,6-Dihydro-1,2,4,6-thiatriazin-5-one-1,1-dioxides of the formula STR1 where R1 is hydrogen, a metal atom or an unsubstituted or substituted ammonium radical, R2 is a saturated or unsaturated straight-chain aliphatic radical of up to 10 carbon atoms, a cycloaliphatic radical or 3 to 7 carbon atoms, a branched saturated or unsaturated aliphatic radical of 3 to 10 carbon atoms, a halogen-, alkoxy- or alkylmercapto-substituted aliphatic radical of 2 to 10 carbon atoms tetrahydrofuryl substituted methyl, a cycloalkoxy-substituted aliphatic radical of 4 to 10 carbon atoms, unsubstituted or halogen-substituted benzyl or phenyl, halophenyl, or alkylphenyl of a total of up to 10 carbon atoms, R3 is hydrogen, a straight-chain aliphatic radical of up to 10 carbon atoms, a cycloaliphatic radical of 3 to 7 carbon atoms, a branched aliphatic radical of 3 to 10 carbon atoms, haloalkyl, or alkoxyalkyl of 2 to 10 carbon atoms and X is oxygen and may also be sulfur if R2 is unsubstituted or halogen-substituted benzyl, processes for their preparation, and herbicides containing the above compounds.
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- THE PREPARATION AND SOME REACTIONS OF 2,3,5,6-TETRACHLOROPHENYLMAGNESIUM CHLORIDE
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The reaction of pentachlorobenzene with metallic magnesium in THF at 10-15 deg C gives after hydrolysis 1,2,4,5-tetrachlorobenzene (76percent) and pentachlorobenzene (8percent); after trimethylsilylation, 1,2,4,5-tetrachloro-3-(trimethylsilyl)benzene (74percent), pentachloro(trimethylsilyl)benzene (8percent) and 1,2,4,5-tetrachlorobenzene (6percent); after iodination, 1,2,4,5-tetrachloroiodobenzene (44percent), pentachloroiodobenzene (12percent) and 1,2,4,5-tetrachlorobenzene (9percent); and finally after carbonation, 2,3,5,6-tetrachlorobenzoic acid (58percent).These products indicate that in the Grignard reaction a mixture of largely 2,3,5,6-tetrachlorophenylmagnesium chloride and some pentachlorophenylmagnesium chloride is formed.The formation of pentachlorophenylmagnesium chloride is explained on the basis of metal-hydrogen exchange reaction between 2,3,5,6-tetrachlorophenylmagnesium chloride and the unreacted pentachlorobenzene.
- Rahman, M. T.
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