Sulfuric acid, chloro

Chlorosulfonic acid Sulfuric acid, chloro- (8,9) (7790-94-5) e-Benzoylaminocaproic acid Hexanoic acid, 6-benzamido- (8) Hexanoic acid, 6-benzoylamino- (9) (956-09-2)... 

On heating tricMoroethylene Tpith formaldehyde solution or paraformaldehyde in the presence of approximatelj 80 per cent sulfuric acid, chloro-acndic acid (CHarCHCl-COOH), the dehydration product of mono-chlorohydiacrylic acid, is obtained. Esters of this acid can be obtained by adding alcohols to the reaction mixture and distilling. These processes haA e been patented by Crawford and McLeish, ... 

Nickel and Cobalt. Often present with copper in sulfuric acid leach Hquors are nickel [7440-02-0] and cobalt [7440-48-4]. Extraction using an organophosphoric acid such as D2EHPA at a moderate (3 to 4) pH can readily take out the nickel and cobalt together, leaving the copper in the aqueous phase, but the cobalt—nickel separation is more difficult (274). In the case of chloride leach Hquors, separation of cobalt from nickel is inherently simpler because cobalt, unlike nickel, has a strong tendency to form anionic chloro-complexes. Thus cobalt can be separated by amine extractants, provided the chloride content of the aqueous phase is carefully controUed. A successhil example of this approach is the Falcon-bridge process developed in Norway (274). 

Several processes are available for the recovery of platinum and palladium from spent automotive or petroleum industry catalysts. These include the following. (/) Selective dissolution of the PGM from the ceramic support in aqua regia. Soluble chloro complexes of Pt, Pd, and Rh are formed, and reduction of these gives cmde PGM for further refining. (2) Dissolution of the catalyst support in sulfuric acid, in which platinum is insoluble. This... 

Later, a completely different and more convenient synthesis of riboflavin and analogues was developed (34). It consists of the nitrosative cyclization of 6-(A/-D-ribityl-3,4-xyhdino)uracil (18), obtained from the condensation of A/-D-ribityl-3,4-xyhdine (11) and 6-chlorouracil (19), with excess sodium nitrite in acetic acid, or the cyclization of (18) with potassium nitrate in acetic in the presence of sulfuric acid, to give riboflavin-5-oxide (20) in high yield. Reduction with sodium dithionite gives (1). In another synthesis, 5-nitro-6-(A/-D-ribityl-3,4-xyhdino) uracil (21), prepared in situ from the condensation of 6-chloro-5-nitrouracil (22) with A/-D-ribityl-3,4-xyhdine (11), was hydrogenated over palladium on charcoal in acetic acid. The filtrate included 5-amino-6-(A/-D-ribityl-3,4-xyhdino)uracil (23) and was maintained at room temperature to precipitate (1) by autoxidation (35). These two pathways are suitable for the preparation of riboflavin analogues possessing several substituents (Fig. 4). 

Hydrogen hahdes normally add to form 1,2-dihaLides, though an abnormal addition of hydrogen bromide is known, leading to 3-bromo-l-chloropropane [109-70-6], the reaction is beUeved to proceed by a free-radical mechanism. Water can be added by treatment with sulfuric acid at ambient or lower temperatures, followed by dilution with water. The product is l-chloro-2-propanol [127-00-4]. 

Chlotobenzoyl)-benzoic acid is nitrated in concentrated sulfuric acid, then reduction of the nitro group, ring closure, and hydrolysis occur simultaneously in concentrated sulfuric acid in the presence of a reducing agent and boric acid. Thus obtained cmde chloro pink is purified by selective precipitation from sulfuric acid in order to separate it from by-produced 2-amino-3-chloto-l-hydroxyanthtaquinone (24) (36). 

Hydroxyphthalazin-l(2//)-one is obtained in a smooth reaction between phthalic anhydride and hydrazine hydrate and this is again the starting compound for many 1-substituted and/or 1,4-disubstituted phthalazines. The transformations of 1,4-dichloro-phthalazine, which is prepared in the usual manner, follow a similar pattern as shown for pyridazines in Scheme 110. On the other hand, phthalonitrile is the preferential starting compound for amino- and hydrazino-phthalazines. The most satisfactory synthesis of phthalazine is the reaction between a,a,a, a -tetrachloro-o-xylene and hydrazine sulfate in sulfuric acid (67FRP1438827), alt iough catalytic dehalogenation of 1-chloro- or 1,4-dichloro-phthalazine or oxidation of 1-hydrazinophthalazine also provides the parent compound in moderate yield. 

The use of free-radical reactions for this mode of ring formation has received rather more attention. The preparation of benzo[Z)]thiophenes by pyrolysis of styryl sulfoxides or styryl sulfides undoubtedly proceeds via formation of styrylthiyl radicals and their subsequent intramolecular substitution (Scheme 18a) (75CC704). An analogous example involving an amino radical is provided by the conversion of iV-chloro-iV-methylphenylethylamine to iV-methylindoline on treatment with iron(II) sulfate in concentrated sulfuric acid (Scheme 18b)(66TL2531). 

Terephthalic acid has been obtained from a great many /)-disubstituted derivatives of benzene or cyclohexane by oxidation with permanganate, chromic acid, or nitric acid. The following routes appear to have preparative value from />-toluic acid, />-methylacetophenone,2 or dihydro-/)-tolualdehyde by oxidation with permanganate from f>-cymene by oxidation with sodium dichromate and sulfuric acid from />-dibromobenzene or from /i-chloro- or -bromobenzoic acid by heating at 250° with potassium and cuprous cyanides and from />-dibromo-benzene, butyllithium, and carbon dioxide. ... 

Linearly annelated 2-methyl-4,9-dioxo-4,9-dihydrooxazolo[4,5-g]quinoline 14 was prepared in 31% yield by cyclization of 6-acetamido-7-chloro-5,8-dioxo-5,8-dihydroquinoline in acetic anhydride and sulfuric acid (59LA108). 

The contents of the tube were then acidified to pH 2 by the addition of sulfuric acid and centrifuged. Examination of the supernatant liquid by paper chromatography employing the methods of 8ohonos et al. Antibiotics Annual (1953-4, page 49), demonstrates the presence of 7-chloro-6-demethyltetracycline, 7-chlorotetracycline and tetracycline. 

Chloro-4-pentanone N-Ethyl-N-2-hydroxyethy I amine 4,7-Dichloroquinoline Sulfuric acid... 

In general, the O-alkylation of benzoxepinones is accomplished via the anion. Alternatively, an acid-catalyzed process employing ortho esters may be used. For the acid-catalyzed formal O-alkylation of l-chloro-8-methoxydibenz[ft,/]oxepin-10(ll//)-ones with triethyl orthoformate rather drastic conditions are required (hot concentrated sulfuric acid) to give the 10-ethoxy derivative 12 in excellent yield.109... 

Alternatively, hydration of the acetylenes in cold concentrated sulfuric acid, or with mercury(II) sulfate in formic acid, yields 1-aryl-3,4-dihydro-5//-2-benzazepin-5-ones which are isolated as their methylsulfonate salts.79 If, however, acetylene 4 is stirred with pyrrolidine at room temperature then cyclization is accompanied by amination to give 8-chloro-l-(2-chlorophenyl)-4-(pyrrolidin-l-yl)-3i/-2-benzazepine (5) in high yield. 

Aluminum phthalocyanine (PcAlX) can be prepared from the phthalonitrile and aluminum trichloride either in refluxing quinoline138 13g or without a solvent under addition of ammonium molybdate(VI).137 The chloro compound can be transformed to a hydroxy derivative by treatment with sulfuric acid.58-140 Also, the insertion of aluminum in a metal-free phthalocyanine is possible, for example trialkylaluminum can be used.141,142... 

Activating groups at the 5-position led to high yields when bromination took place in chloroform or acetic acid. Products obtained were the 4-bromo derivatives of 5-amino- (90%), 5-hydroxy- (95%), and 5-methoxy-benzisothiazole (40%). Use of the bromine-sulfuric acid-silver sulfate system raised the yield of the last-named product to 87% [80JCR(S)197], 7-Amino-4-chloro-l,2-benzisothiazole was brominated in the 6-position [71JCS(C)3994],... 

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