Reaction products, liquid mixture

Cool the mixture and pour the liquid reaction product into a separating-funnel. Rinse out the flask (which may contain some unchanged zinc) with ether, pour the latter into the funnel, and extract the aqueous solution with the ether. Repeat the extrac tion with a second quantity of ether, unite the ether extracts, wash them by extracting once with water, and then dry the ethereal extract over sodium sulphate. 

Tetrahydrofurfuryl chloride. Place 204 g. (194 ml.) of freshly distilled tetrahydrofurfuryl alcohol (b.p. 177°) and 174 g. (178 ml.) of dry pyridine in a 1-litre three-necked flask, fitted with a dropping funnel, mechanical stirrer and thermometer. Cool in an ice bath, stir vigorously and add 250 g. (153 ml.) of freshly distilled thionyl chloride at the rate of 3-5 drops per second. A pasty crystalline mass begins to separate and the temperar ture commences to rise rapidly when one-third to one-half of the thionyl chloride has been added subsequently the mass largely redissolves and a dark brown liquid forms. Remove the ice bath when the addition is complete and stir the mixture for 3-4 hours. Pour the reaction product into a large separatory funnel and extract with seven 250 ml. portions of ether break up any lumps that may form with a glass rod. Remove the ether from the combined extracts by distillation, wash the residue with three 50 ml. portions of water, dry with anhydrous magnesium sulphate and distil under reduced pressure. The yield of tetrahydrofurfuryl chloride, b.p. 47-48°/15 mm., is 180 g. 

Equip a 1 litre bolt-head flask with dropi)ing fuuncl and a double surface reflux condenser to the top of the latter attach a device (e.g.. Fig. II, 8, 1. c) for the absorption of the hydrogen bromide evolved. Place 100 g. (108 ml.) of dry iso-valeric acid (Section 111,80) and 12 g. of pmified red phosphorus (Section 11,50,5) in the flask. Add 255 g. (82 ml.) of dry bromine (Section 11,49,5) slowly through the dropping funnel at such a rate that little or no bromine is lost with the hydrogen bromide evolved the addition occupies 2-3 hours. Warm the reaction mixture on a water bath until the evolution of hydrogen bromide is complete and the colour of the bromine has disappeared. Pour off the liquid reaction product into a Claisen flask and distil mider the reduced pressure of a water pump. Collect the a-bromo-wo-valeryl bromide at 117-122°/25-30 mm. The yield is 150 g. 

Liquid-phase oxidation of lower hydrocarbons has for many years been an important route to acetic acid [64-19-7]. In the United States, butane has been the preferred feedstock, whereas ia Europe naphtha has been used. Formic acid is a coproduct of such processes. Between 0.05 and 0.25 tons of formic acid are produced for every ton of acetic acid. The reaction product is a highly complex mixture, and a number of distillation steps are required to isolate the products and to recycle the iatermediates. The purification of the formic acid requires the use of a2eotropiag agents (24). Siace the early 1980s hydrocarbon oxidation routes to acetic acid have decliaed somewhat ia importance owiag to the development of the rhodium-cataly2ed route from CO and methanol (see Acetic acid). 

Purification of a chemical species by solidification from a liquid mixture can be termed either solution crystallization or ciystallization from the melt. The distinction between these two operations is somewhat subtle. The term melt crystallization has been defined as the separation of components of a binaiy mixture without addition of solvent, but this definition is somewhat restrictive. In solution crystallization a diluent solvent is added to the mixture the solution is then directly or indirec tly cooled, and/or solvent is evaporated to effect ciystallization. The solid phase is formed and maintained somewhat below its pure-component freezing-point temperature. In melt ciystallization no diluent solvent is added to the reaction mixture, and the solid phase is formed by cooling of the melt. Product is frequently maintained near or above its pure-component freezing point in the refining sec tion of the apparatus. 

A mixture of 60 g (0.408 mol) of isatin, 200 mL of 34% potassium hydroxide in diluted alcohol solution, 88 g (1.22 mol) of ethyl methyl ketone and 375 mL of water were stirred and heated under reflux for 72 hours. About 125 mL of liquid was removed by distillation the residue was made slightly acidic and filtered. The filtrate was made strongly acidic to precipitate the reaction product, which was collected by filtration, washed, dried, weighed 70 g (85% yield). 

Schimmel Co. attempted to acetylise the alcohol by means of acetic anhydride, but the reaction product only showed 5 per cent, of ester, which was not submitted to further examination. The bulk of the alcohol had been converted into a hydrocarbon, with loss of water. Ninety per cent, formic acid is most suitable for splitting off water. Gne hundred grams of the sesquiterpene alcohol were heated to boiling-point with three times the quantity of formic acid, well shaken, and, after cooling, mixed with water. The layer of oil removed from the liquid was freed fi-om resinous impurities by steam-distillation, and then fractionated at atmo.spheric pressure. It was then found to consist of a mixture of dextro-rotatory and laevo-rotatory hydrocarbons. By repeated fractional distillation, partly in vacuo, partly at ordinary pressure, it was possible to separate two isomeric sesquiterpenes, which, after treatment with aqueous alkali, and distillation over metallic sodium, showed the following physical constants —... 

Most of the inhibitors in use are organic nitrogen compounds and these have been classified by Bregman as (a) aliphatic fatty acid derivatives, b) imidazolines, (c) quaternaries, (d) rosin derivatives (complex amine mixtures based on abietic acid) all of these will tend to have long-chain hydrocarbons, e.g. CigH, as part of the structure, (e) petroleum sulphonic acid salts of long-chain diamines (preferred to the diamines), (/) other salts of diamines and (g) fatty amides of aliphatic diamines. Actual compounds in use in classes (a) to d) include oleic and naphthenic acid salts of n-tallowpropylenediamine diamines RNH(CH2) NH2 in which R is a carbon chain of 8-22 atoms and x = 2-10 and reaction products of diamines with acids from the partial oxidation of liquid hydrocarbons. Attention has also been drawn to polyethoxylated compounds in which the water solubility can be controlled by the amount of ethylene oxide added to the molecule. 

The reaction product, which is a dark reddish-brown liquid, is poured or siphoned (Note 5) into 1.5 1. of water to which 50 cc. of a saturated solution of sodium bisulfite has been added (Note 6). The mixture is distilled with steam (Org. Syn. 2, 80) and the first portion of the distillate is collected separately to remove a small amount of unchanged nitrobenzene. It is necessary to collect about 12 1. of distillate in order to obtain all of the m-bromonitrobenzene. The yellow crystalline solid is filtered with suction and pressed well on the funnel to remove water and traces of nitrobenzene. The yield of crude product varies from 270-340 g. (60-75 Per cent °f the theoretical amount). It melts at 51.5-520 and boils at 117-118 79 mm. This product is satisfactory for most purposes. If a purer material is desired, the crude /w-bromonitrobenzene may be distilled under reduced pressure. The recovery on purification is about 85 per cent. Briihl recorded the b.p. as 1380/18 mm. and the m.p. as 56° for pure wz-bromonitrobenzene.1... 

A solution of a 2-aminobenzophenone (0.1 mol) and an z-amino acid ethyl ester hydrochloride (0.15 mol) in pyridine (200 mL) was refluxed. During the first 4h, 20-50 mL of liquid was allowed to distill and was replaced by fresh pyridine. Heating was continued for a further 11 h, the mixture was evaporated under reduced pressure and H20 and Et20 were added. In most cases some of the reaction product remained undissolved and was filtered off. The aqueous layer was separated, made alkaline and extracted with Et20. The comhined F.t20 phases were washed with H20. dried and evaporated and the reaction product was separated from unchanged amino ketone by crystallization. 

The paraffin wax is oxidized by air in a liquid phase process at 110-130°C. Catalysts for this radical reaction are cobalt or manganese salts [54]. The quality of the obtained mixture of homologous carboxylic acids is impaired by numerous byproducts such as aldehydes, ketones, lactones, esters, dicarboxylic acids, and other compounds. These are formed despite a partial conversion of the paraffin and necessitate an expensive workup of the reaction product [50,55]. 

Acetic acid and 10, 15, or 20% acetyl chloride were fed as a mixture into a modified falling film micro reactor (also termed micro capillary reactor in [57]) at a massflow rate of 45 g min and a temperature of 180 or 190 °C [57]. Chlorine gas was fed at 5 or 6 bar in co-flow mode so that a residual content of only 0.1% resulted after reaction. The liquid product was separated from gaseous contents in a settler and collected. By exposure to water, acetyl chloride and acetic anhydride were converted to the acid. The hydrogen chloride released was removed. 

A significant proportion of products are solids that are separated from a reaction mixture by filtration and centrifugation and purified by crystallization. Recently, more sophisticated techniques for purification (e.g. HPLC) have come in use but crystallization still remains the predominant method. In order to separate solid/liquid mixtures, centrifuges and plane filters (nutches) are u.sed. Generally, filters and centrifuges are operated batchwise. No specific... 

The reductive carbonylation has an advantage of low feedstock cost. A wide range of homogenous metal complexes have been tested for both reactions (1-16). The major drawback of the use of metal complex catalysts is the difficulty of catalyst recovery and purification of the reaction products (12). In addition, the gaseous reactants have to be dissolved in the alcohol/amine mixture in order to have an access to the catalyst. The reaction is limited by the solubility of the gaseous CO and 02 reactants in the liquid alcohol reactant (17). 

C30 oil, homopolymer of 1-decene, Ethyl Corp., Inc.) served as the start-up solvent for the experiments. The catalyst (ca. 5-8 g) was added to start-up solvent (ca. 300 g) in the CSTR. The reactor temperature was then raised to 270°C at a rate of l°C/min. The catalyst was activated using CO at a space velocity of 3.0 sl/h/g Fe at 270°C and 175 psig for 24 h. FTS was then started by adding synthesis gas mixture (H2 CO ratio of 0.7) to the reactor at a space velocity of either 3.1 or 5.0 sl/h/g Fe. The conversions of CO and H2 were obtained by gas chromatography (GC) analysis (HP Quad Series Micro-GC equipped with thermal conductivity detectors) of the product gas mixture. The reaction products were collected in three traps maintained at different temperatures—a hot trap (200°C), a warm trap (100°C), and a cold trap (0°C). The products were separated into different fractions (rewax, wax, oil, and aqueous) for quantification by GC analysis. However, the oil and the wax (liquid at room temperature) fractions were mixed prior to GC analysis. 

In recent studies, a new line of PGM collectors had been developed [13] known as the PM series. These collectors are an ester-modified mixture of xanthate + mercaptan. The reaction product forms an oily greenish-coloured liquid. The results obtained using the PM series of collectors are shown in Table 18.5. High PGM recovery was obtained using a combination of sodium amyl xanthate plus collector PM301. 

If nonvolatile liquids are to be used to avoid the problems associated with volatile organic solvents, then it is very desirable that there is some convenient way of recovering the reaction products from the liquid. This approach is used in the biphasic systems described in Chapters 2-5. In the fluorous biphase (Chapter 3), reagents and catalysts are fine-tuned by adding perfluoroalkyl chains, known as ponytails , to ensure that only those chemicals will mix with the fluorous layer. Purification is simply a matter of separating the two phases. Transition metal catalysts with fluorous ligands will remain in the fluorous phase, and the whole catalyst-solvent mixture may be reused for another batch of reactions, as shown schematically in Figure 1.20b. 

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