- A method of removing chlorosulfonic acid in pentachlorobenzoyl chloride production
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A method of removing chlorosulfonic acid in pentachlorobenzoyl chloride production is disclosed. The method includes (1) feeding chlorine and reacting to produce pentachlorobenzoyl chloride by adopting benzoyl chloride as a raw material and chlorosulfonic acid as a solvent, (2) subjecting the chlorination solution generated in the step (1) to vacuum recovering, (3) cooling the recovered solution to 60-100 DEG C by jacket water cooling, sampling and detecting the content of residual high-oxidizability acids, (4) allowing the mole ratio of sulfuric acid in the recovered solution to sodium chloride to be 1:(2.10-2.5) and reacting the sulfuric acid and the sodium chloride to generate HCl and sodium sulfide, (5) allowing the mole ratio of the chlorosulfonic acid in the recovered solution to sodium bicarbonate to be 1:(0.9-1.0), and (6) allowing the mixture to stand, depositing, centralizing, and subjecting solid to filtration and washing with a solvent to further recover a product. The method has characteristics of cost saving, good product quality, a simple process, easy operation, low environment pollution, and the like.
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Paragraph 0028; 0029
(2017/06/08)
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- Reactions of dimethoxycarbene with cyclic perchlorinated olefins and ketones
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Reactions of dimethoxycarbene (2), a carbonyl group equivalent, with perchlorinated olefins and ketones were investigated. Thermolysis of 2,2- dimethoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline (1) at 110 °C generated 2, which reacted with hexachlorocyclopentadiene (4), octachlorocycloheptatriene (12), octachlorobicyclo[3.2.0]hepta-3,6-diene (24), hexachlorotropone (28), hexachlorobicyclo[3. 2.0]-hepta-3,6-dien-2-one (32), and tetrachloro-1,4- benzoquinone (35). Reactions of 2 with perchlorinated olefins 4, 12, and 24 led to esters or, in the case of 12, to a ketene acetal. Their formation is rationalized in terms of Michael-like addition and displacement (S(N)2' or S(N)2', if concerted) of allylic chlorine atoms by 2, yielding ion pairs that either dechloromethylate to esters or dechlorinate to a ketene acetal. In contrast, the reactions of 2 with unsaturated perchloroketones 28, 32, and 35 led to ring contraction, ring expansion, and aromatization, respectively. The products from these reactions are consistent with nucleophilic addition of 2 at the carbonyl moiety rather than Michael-type addition. Dimethoxycarbene- d3 was used to show that demethylation in the latter reaction was intermolecular. Mechanisms for the different reaction courses are proposed.
- Dunn, James A.,Pezacki, John Paul,McGlinchey, Michael J.,Warkentin, John
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p. 4344 - 4352
(2007/10/03)
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- Photochemical Behavior of Stable Free Radicals: The Photochemistry of Perchlorodiphenylmethyl Radical
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The excitation of perchlorodiphenylmethyl radical (PDM) at 530 nm leads to the lowest excited doublet, D1 (τ = 31 ns), from which emission is observed (Φ = 1 x 10-3 +/- 0.0003).This state is quenched by electron donors and acceptors at a rate at or close to diffusion control and at much slower rates by oxygen and hydrogen atom donors.Fragmentation of PDM (Φd = 0.06) occurs from a higher excited doublet (Dn, n > = 2) producing intermediates that are trapped by O2, chlorine, or hydrogen donors, yielding products 1-6.Experimental evidence suggests a structure-photoreactivity correlation in the perchlorinated arylmethyl radicals in which the partitioning between photochemical cyclization or fragmentation depends on the twist angle between the appended phenyl rings.
- Ruberu, Shiyamalie,Fox, Marye Anne
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p. 143 - 149
(2007/10/02)
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- Process for the preparation of halogenated benzoyl fluorides
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A process for the preparation of a halogenated benzoyl fluoride, which comprises contacting a halogenated benzotrifluoride of the formula STR1 in which m and n independently of one another represent an integer from 0 to 5, the sum of m and n being 5, with at least one sulphur compound of the formula STR2 in which X denotes fluorine, chlorine or hydroxyl and Y represents hydroxyl, or X and Y together denote an oxygen atom linked to the sulphur atom by a double bond, at an elevated temperature, and after reaction with the halogenated benzotrifluoride, removing the sulphur compound from the reaction mixture in the form of a compound of the formula STR3 in which X has the meaning given and Hal represents fluorine or chlorine, the reaction product is further reacted with potassium fluoride at an elevated temperature and under increased pressure.
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