Zinc chloride fused

Lucas reageut is prepared by dissolving 68 g. (0-5 mole) of anhydrous zinc chloride (fused sticks, powder, etc.) in 62 6 g. (0 6 mole) of concentrated hydrochloric acid with cooling to avoid loss of hydrogen chloride. 

Other reagents are available for introducing the 2-oxo group. Thus, 2-amino-3-pyridyl phenyl ketone, ethyl carbamate, and zinc chloride, fused for 45 min at 230°C, gave a good yield of 4-phenylpyrido[2,3-d ] pyrimidin-2-one (see 3). In addition, 2-ferf-butylamino-3-pyridylphenylketonimine, phosgene, and triethylamine, stirred in cold benzene for 10 min, produced... 

Phenolsulphonephthalein (phenol red). Mix 10 g. of o-sulpho-benzoic anhydride (Section VIII,9), 14 g. of pure phenol and 10 g. of freshly fused zinc chloride in a small conical flask. Place a glass rod in the flask and heat gently over a flame to melt the phenol. Then heat the flask containing the well-stirred mixture in an oil bath at 135-140° for 4 hours. Stir from time to time, but more frequently during the first hour if the mixture froths unduly, remove the flask from the bath, cool and then resume the heating. When the reaction is complete, add 50 ml. of water, allow the water to boil and stir to disintegrate the product. Filter the crude dye with suction and wash it well with hot water. Dissolve the residue in the minimum volume of warm (60°) 20 per cent, sodium hydroxide solution, filter, and just acidify the filtrate with warm dilute hydrochloric acid (1 1). Filter the warm solution, wash with water, and dry upon filter paper. The yield of phenol red (a brilliant red powder) is 11 g. 

Anhydrous zinc chloride can be made from the reaction of the metal with chlorine or hydrogen chloride. It is usually made commercially by the reaction of aqueous hydrochloric acid with scrap zinc materials or roasted ore, ie, cmde zinc oxide. The solution is purified in various ways depending upon the impurities present. For example, iron and manganese precipitate after partial neutralization with zinc oxide or other alkah and oxidation with chlorine or sodium hypochlorite. Heavy metals are removed with zinc powder. The solution is concentrated by boiling, and hydrochloric acid is added to prevent the formation of basic chlorides. Zinc chloride is usually sold as a 47.4 wt % (sp gr 1.53) solution, but is also produced in soHd form by further evaporation until, upon cooling, an almost anhydrous salt crystallizes. The soHd is sometimes sold in fused form. 

When the triazole was heated with fused zinc chloride at 320° the main produet was 3-anilinopyridine (198) together with a small amount of jS-carboline. From the j8-carbohne mother liquors a small quantity of a product, m.p. 214—215°, was isolated. On the basis of the fact that this product was different from a- or y-carbohne, and though the... 

B) t-Butyl 2-Methyl-5-Methoxy-3-lndolylacetate t-Butyl alcohol (25 ml) and fused zinc chloride (0.3 g) are added to the anhydride from Part A. The solution is refluxed for 16 hours and excess alcohol is removed in vacuo. The residue is dissolved in ether, washed several times with saturated bicarbonate, water, and saturated salt solution. After drying over magnesium sulfate, the solution is treated with charcoal, evaporated, and flushed several times with Skellysolve B for complete removal of alcohol. The residual oily ester (18 g, 93%) is used without purification. 

F. P. Haver, D. E. Shanks, D. L. Bixby and M. M. Wong, Recovery of Zinc from Zinc Chloride by Fused Salt Electrolysis, U. S. Bureau of Mines, Rept. Invst. No. 8133,1976. 

Preparation of 3 - Chloro-6 -cyclohexylaminoJluoran (85a). A mixture of 3, 6 -dichlorofluoran (0.1 mol), cyclohexylamine hydrochloride (0.15 mol), zinc chloride (0.3 mol), and zinc oxide (0.2 mol) was fused at 190-200 °C for 4 h. After being cooled, the solidified mixture was powdered, heated with 4% hydrochloric acid (1000 ml) to dissolve zinc chloride, and filtered. Then, the filter cake was refluxed with a mixture of toluene (400ml) and 5% aqueous sodium hydroxide (100 ml) for 1 h. The toluene layer was separated, washed with hot water, and concentrated. The residue was refluxed with methanol (200ml) for 1 h. After being cooled, the precipitate was filtered off, washed with methanol, and dried to give 3 -chloro-6 -cyclohexylaminofluoran in 60% yield as an off-white powder, mp 178-181 °C. 

Preparation of the Leuco-Base—Zinc chloride (10 g.) is fused in a porcelain basin, cooled, and powdered. It is then added to a mixture of 25 g. of dimethylaniline and 10 g. of benzaldehyde (both freshly distilled) and the whole is heated in a porcelain basin on the water bath with frequent stirring for four hours. By the addition of hot water the viscous mass is liquefied on the water bath and the hot liquid is poured into a half-litre flask into which steam is passed until drops of oil cease to distil. After the liquid has cooled the water is poured off and the residue is washed several times with water. When as much as possible of the water has been removed the material in the flask is dissolved by adding alcohol and warming on the water bath, and the solution is filtered. On leaving the filtrate over night in a cool place the base separates in colourless crystals which are collected at the pump, washed with alcohol and dried in air on several folds of filter paper. A second crop of crystals can be obtained by concentrating the mother liquor. Should the base not crystallise, but separate as an oil—as often happens after the filtered solution has stood for a short time—it follows that too little alcohol has been used. In such cases somewhat more alcohol is added and the mixture is heated until the oil dissolves. Yield 20-24 g. 

Phenyl cinnamate and other phenolic esters have been prepared by heating the acid and phenol in the presence of phosphorus oxychloride,1 and by heating the acid anhydride and phenol together in the presence of a dehydrating agent such as fused zinc chloride or anhydrous sodium acetate.2 Phenyl cinnamate has also been prepared by the careful distillation of phenyl fumarate.3... 

Several methods are available for producing thorium metal it can be obtained by reducing thorium oxide with calcium, by electrolysis of anhydrous thorium chloride in a fused mixture of sodium and potassium chlorides, by calcium reduction of thorium tetrachloride mixed with anhydrous zinc chloride, and by reduction of thorium tetrachloride with an alkali metal. 

To a solution of/t-chlorophenylmagnesium bromide prepared from 0.29 gm (0.012 gm-atom) of magnesium and 2.1 gm (0.011 mole) of 4-chlorobromo-benzene in 30 ml of anhydrous ether is added 1.1 gm (0.011 mole) of freshly fused anhydrous zinc chloride in 50 ml of anhydrous ether. The resulting solu-... 

B. 2,3,4,5,6-Penta-O-acetyl-v-gluconic acid. Tetra-O-acetyl-D-gluconic acid monohydrate (50 g., 0.13 mole) is slowly added to a chilled (0-5°) solution of 18 g. of fused zinc chloride in 190 ml. of acetic anhydride contained in a 1-1. Erlenmeyer flask. The solution is kept in an ice bath for an hour and then allowed to stand at room temperature for 24 hours. After dilution with 1 1. of water, the solution is extracted with four 100-ml. portions of chloroform. In order to remove the chloroform, 200 ml. is distilled, 250 ml. of toluene is added, and 250 ml. of this solution is distilled. Another 250 ml. of toluene is then added and the volume is reduced to 300 ml. The product crystallizes on standing at 0° (Note 2). The solid is removed by filtration, washed with toluene and then with petroleum ether (b.p. 35-55°). A yield of 44-45 g. (83-84%) of anhydrous 2,3,4,5,6-penta-O-acetyl-D-gluconic acid, melting at 110-111°, is obtained [o ]d + 11.5° (c = 4.0 in ethanol-free chloroform). 

A. 2,3,4,6-Tetra-O-acetyl-T)-gluconic acid monohydrate. Crushed, fused zinc chloride (20 g.) is shaken with 250 ml. of acetic anhydride in a 1-1. three-necked flask until most of the solid... 

The detection and determination ot the perchlorates.—The perchlorates give no precipitates with silver nitrate or barium chloride soln. cone. soln. give a white crystalline precipitate with potassium chloride. Unlike all the other oxy-acids of chlorine, a soln. of indigo is not decolorized by perchloric acid, even after the addition of hydrochloric acid and they do not give the explosive chlorine dioxide when warmed with sulphuric acid unlike the chlorates, the perchlorates are not reduced by the copper-zinc couple, or sulphur dioxide. Perchloric acid can be titrated with —iV-alkali, using phenolphthalein as indicator. The perchlorates can be converted into chlorides by heat and the chlorides determined volumetrically or gravimetrically they can be reduced to chloride by titanous sulphate 28 and titration of the excess of titanous sulphate with standard permanganate they can be fused with zinc chloride and the amount of chlorine liberated can be measured in terms of the iodine set free from a soln. of potassium iodide and they can be... 

Ethyl l-thio-/3-maltoside heptaaeetate (59) has proved to be a useful intermediate in the synthesis of the a-glycoside of maltose (see Section III).30 Treatment of /3-maltose octaacetate with ethanethiol and fused zinc chloride gave compound 59 in 83% yield. Synthesis of mal-... 

Proton acids can be used as catalysts when the reagent is a carboxylic acid. The mixed carboxylic sulfonic anhydrides RCOOSO2CF3 are extremely reactive acylating agents and can smoothly acylate benzene without a catalyst.265 With active substrates (e.g., aryl ethers, fused-ring systems, thiophenes), Friedel-Crafts acylation can be carried out with very small amounts of catalyst, often just a trace, or even sometimes with no catalyst at all. Ferric chloride, iodine, zinc chloride, and iron are the most common catalysts when the reactions is carried out in this manner.266... 

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