- Method of making halophthalic acids and halophthalic anhydrides
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A method of preparing a halophthalic acid is disclosed which comprises the steps of contacting in a liquid phase reaction mixture at least one halogen-substituted ortho-xylene with oxygen and acetic acid at a temperature in a range between about 120° C. and about 220° C. in the presence of a catalyst system yielding a product mixture comprising less than 10 percent halogen-substituted ortho-xylene starting material, a halophthalic acid product, and less than about 10,000 ppm halobenzoic acid and less than about 1000 ppm halophthalide by-products based on a total amount of halophthalic acid present in the product mixture. In addition a method for the preparation of halophthalic anhydride is also disclosed.
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Page/Page column 9
(2008/06/13)
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- Processes using a phosphorus complex
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A process for chlorinating compounds containing a carbon atom bonded to a hetero-atom selected from the group consisting of oxygen, nitrogen and sulfur; said process comprises contacting the carbon hetero-atom containing compound with a chloro phosphorus complex of the formula wherein R is selected from the group consisting of aryl, substituted aryl, alkyl and substituted alkyl, so that the hetero-atom is replaced by at least one chlorine atom; compounds capable of being chlorinated can include, for example, carboxylic acids, acid chlorides, ketones, aldehydes, alcohols, epoxides, esters, anhydrides, ethers, thiols, and aromatic nitro groups; the reaction can be extended to compounds containing the carbon to chlorine bond alpha to a carbon atom containing at least one hydrogen atom, it can be further dehydrochlorinated, e.g., by either heating to a temperature ranging from about 50° C. to about 300° C. or by reaction with a base selected, e.g., from alkali metal hydroxides and alkoxides.
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- On the regioselectivity of metal hydride reductions of 3-substituted phthalic anhydrides
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A problem of 3-methoxyphthalide reduction by metal hydrides was reinvestigated. Various effects controlling selectivity of reductions in 3-substituted phthalides were studied, and a qualitative interpretation of the results is now proposed. Methods for obtaining enhanced yields of one or the other lactonic product were developed.
- Soucy,Favreau,Kayser
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p. 129 - 134
(2007/10/02)
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- Flame retardant for polymeric compositions
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An additive flame retardant bisimide containing halogen atoms and ammonium acid tetrahalophthalate, e.g. N,N'-bis(2-ethylene tetrabromophthalimide) ammonium acid tetrabromophthalate. These compounds are useful in a variety of polymeric compositions and demonstrate increased thermal stability. They also foam on decomposition with the evolution of gas thus readily lending themselves to the preparation of flame retardant coatings.
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- Remarkably Selective Chlorination of Phthalic Anhydride and Its Monochlorinated Derivatives
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The vapor-phase chlorination of phthalic anhydride 1 and its monochlorinated derivatives 2 and 3 in the temperature range from 390 to 600 deg C with elemental chlorine has been investigated and found to be highly selective.Thus, chlorination of 1 in the temperature range from 390 to 450 deg C was found to give high yields of monochlorinated products accompanied by only small amounts of dichlorination with a high degree of regioselectivity favoring the formation of 4-chlorophthalic anhydride.Chlorination of a 3-chlorophthalic anhydride 3 by this method has provided thefirst direct synthesis of 3,5-dichlorophthalic anhydride 7 from phthalic anhydride via chlorination.
- Verbicky, John W.,Williams, Louella
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p. 2465 - 2468
(2007/10/02)
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- The Schmidt reaction of anthraquinones
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Schmidt reaction (sodium azide/sulfuric acid) of 1,5- and of 1,8-dichloroanthraquinones gives, in each case, both of the theoretically possible lactams (2,3,5,6-dibenzoazepin-4,7-diones).Two of the four theoretically possible lactams have been identified from Schmidt reaction of 1- and 2-chloroanthraquinones respectively.Methods used include:(a) preferential hydrolysis of one lactam and identification of the isomeric aminoanthraquinone formed on cyclodehydration of the resulting amino acid; (b) identification of the isomeric aminoanthraquinone(s) formed on direct treatment of a lactam (or mixture of lactams) by sulfuric acid; (c) cleavage by potassium tert-butoxide of the amino acid formed by preferential hydrolysis of one lactam and identification of the resulting benzoic acid as its methyl ester.
- Flemming, Cecily A.,Gandhi, Sham S.,Gibson, Martin S.,Ruediger, Edward H.
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p. 624 - 628
(2007/10/02)
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- Aspects of Tautomerism: Part X - Neighbouring Group Effects on the Structure and Reactivity Patterns of Acid Chlorides
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The influence of neighbouring groups on the structure and reactivity patterns of over one hundred acid chlorides derived from γ- and δ-keto acids, 1,2- and 1,3-dicarboxylic acid half-esters and diacid chlorides have been examined.Contrary to reports in the literature, text books and monographs, evidence has been obtained for the non-existence of tautomerism between the isomeric pairs of either acid chlorides or half-ester acid chlorides.ce.
- Bhatt, M. Vivekananda,El Ashry, Shaker H.,Somayaji, Vishwanatha
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p. 473 - 486
(2007/10/02)
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