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Distilling off solvents

Fig. 11, 13, 4 shows an assembly which is useful inter alia for distilling off solvents from solutions. The solution is placed in the separatory... [Pg.87]

The assembly shown in Fig. 2.101 is useful for distilling off solvent from solutions, as would be obtained for example from solvent extraction procedures. The... [Pg.170]

The solvents commonly used were diethyl ether, benzene (not then recognised as a carcinogen), ethyl alcohol and acetone. Once the staff numbered four or five, a set-up to distil-off solvent from the collected reaction solutions ran every day so that the solid residues could be returned to Johnson Matthey for recovery. Chatt s first secretary still has a vivid recollection of the numerous fires that occurred (about once a month) but fortunately these were always put out before serious damage was done. On one occasion, when Chatt was bringing a distinguished visitor from the house to the lab., he noticed from a distance that a thick cloud of black smoke was pouring out of the fume-cupboard chimney and took the visitor to the arboretum to see an outstanding example of a maidenhair fern instead. [Pg.12]

Alternatively, the following procedure for isolating the glycol may be used. Dilute the partly cooled mixture with 250 ml. of water, transfer to a distilling flask, and distil from an oil bath until the temperature reaches 95°. Transfer the hot residue to an apparatus for continuous extraction with ether (e.g.. Fig. II, 44, 2). The extraction is a slow process (36-48 hours) as the glycol is not very soluble in ether. (Benzene may also be employed as the extraction solvent.) Distil off the ether and, after removal of the water and alcohol, distil the glycol under reduced pressure from a Claisen flask. [Pg.251]

The following is a modification of the process described and gives quite satisfactory results. Wash the crude mixture of benzonitrile and dibromopentane with sodium carbonate solution until the latter remains alkaline, and then with water. Distil it under reduced pressure and collect the fraction boiling up to 120°/18 mm. Dissolve this in twice its volume of light petroleum, b.p. 40-60°, which has previously been shaken with small volumes of concentrated sulphuric acid until the acid remains colourless. Shake the solution with 6 per cent, of its volume of concentrated sulphuric acid, allow to settle, and run ofi the sulphuric acid layer repeat the extraction until the acid is colourless or almost colourless. Wash successively with water, sodium carbonate solution and water, dry over anhydrous calcium chloride or calcium sulphate, and distil off the solvent. Distil the residue under diminished pressure and collect the 1 6-dibromopentane at 98- 100°/13 mm. [Pg.493]

Beckmann rearrangement of benzophenone oxime to benz-anilide. Dissolve 2 g. of benzophenone oxime in 20 ml. of anhydrous ether in a small conical flask and add 3 g. of powdered phosphorus pentachloride (or 3 ml. of pure tbionyl chloride). Distil off the solvent and other volatile products on a water bath CAUTION ether), add 25 ml. of water, boil for several minutes and break up any lumps which may be formed. Decant the supernatant liquid, and recrystallise, in the same vessel, from boiling alcohol. The product is benzanilide, m.p. 163° confirm this by a mixed m.p. determination with an authentic specimen. [Pg.741]

Method 1. Equip a 1 litre three-necked flask (or bolt-head flask) with a separatory funnel, a mechanical stirrer (Fig. II, 7, 10), a thermometer (with bulb within 2 cm. of the bottom) and an exit tube leading to a gas absorption device (Fig. II, 8, 1, c). Place 700 g. (400 ml.) of chloro-sulphonic acid in the flask and add slowly, with stirring, 156 g. (176 ml.) of pure benzene (1) maintain the temperature between 20° and 25° by immersing the flask in cold water, if necessary. After the addition is complete (about 2 5 hours), stir the mixture for 1 hour, and then pour it on to 1500 g. of crushed ice. Add 200 ml. of carbon tetrachloride, stir, and separate the oil as soon as possible (otherwise appreciable hydrolysis occurs) extract the aqueous layer with 100 ml. of carbon tetrachloride. Wash the combined extracts with dilute sodium carbonate solution, distil off most of the solvent under atmospheric pressure (2), and distil the residue under reduced pressure. Collect the benzenesulphonyl chloride at 118-120°/15 mm. it solidifies to a colourless sohd, m.p. 13-14°, when cooled in ice. The yield is 270 g. A small amount (10-20 g.) of diphen3 lsulphone, b.p. 225°/10 mm., m.p. 128°, remains in the flask. [Pg.822]

Add 50 g. of the crude acetothiomorpholide to 400 ml. of 10 per cent, alcoholic sodium hydroxide solution and reflux the mixture for 10 hours. Distil off most of the alcohol, add 100 ml. of water to the residue, and strongly acidify the alkahne solution with hydrochloric acid. Cool, extract thrice with ether, dry the combined ether extracts, evaporate the solvent, and recrystallise the residue from water or dilute alcohol. The yield of p-methoxyphenylacetic acid, m.p. 85-86°, is 26 g. A further quantity of acid may be obtained by extracting the mother hquors with ether. [Pg.925]

Section IV,49). Reflux the mixture for 1 hour and allow to cool, with continuous stirring. Distil off the methyl alcohol. Add hot water to the residue, filter from impurities, extract the antipyrine with benzene, and evaporate the solvent. RecrystaUise the crude product from benzene or benzene - hght petroleum or from hot water wdth the addition of a little decolomising carbon. The yield of antipyrin (white crystalline solid, m.p. 113°) is 3o g. [Pg.999]

Method 2. Ethyl p-nitrobenzoate. Place 21 g. of p-nitrobenzoic acid (Section IV,154), 11-5 g. of absolute ethyl alcohol, 3 8 g. of concentrated sulphuric acid, and 30 ml. of sodium-dried A.R. benzene in a 250 ml. round-bottomed flask, fit a reflux condenser, and heat the mixture under reflux for 16 hours. Add 50 ml. of ether to the cold reaction mixture, wash the extract successively with sodium bicarbonate soiution and water, dry with anhydrous magnesium sulphate or calcium chloride, and distil off the solvent on a water bath. Remove the last traces of benzene either by heating in an open evaporating dish on a water bath or in a bath at 100-110°. The residual ethyl p-nitrobenzoate (21 g.) solidifies completely on cooling and melts at 56°. [Pg.1001]

Hydrolysis of a sulphonamide. Mix 2 g. of the sulphonamide with 3-5 ml. of 80 per cent, sulphuric acid in a test-tube and place a thermometer in the mixture. Heat the test-tube, with frequent stirring by means of the thermometer, at 155-165° until the solid passes into solution (2-5 minutes). Allow the acid solution to cool and pour it into 25-30 ml. of water. Render the resulting solution alkaline with 20 per cent, sodium hydroxide solution in order to liberate the free amine. Two methods may be used for isolating the base. If the amine is volatile in steam, distil the alkaline solution and collect about 20 ml. of distillate extract the amine with ether, dry the ethereal solution with anhydrous potassium carbonate and distil off the solvent. If the amine is not appreciably steam-volatile, extract it from the alkaline solution with ether. The sulphonic acid (as sodium salt) in the residual solution may be identified as detailed under 13. [Pg.1077]

Step 3. The neutral components. The ethereal solution (E remaining after the acid extraction of Step 2 should contain only the neutral compounds of Solubility Groups V, VI and VII (see Table XI,5). Dry it with a little anhydrous magnesium sulphate, and distil off the ether. If a residue is obtained, neutral compounds are present in the mixture. Test a portion of this with respect to its solubility in concentrated sulphuric acid if it dissolves in the acid, pour the solution slowly and cautiously into ice water and note whether any compound is recovered. Examine the main residue for homogeneity and if it is a mixture devise procedures, based for example upon differences in volatility, solubility in inert solvents, reaction with hydrolytic and other reagents, to separate the components. [Pg.1096]

As you are about to see, the standard methods for using the NaBH(OAc)3 catalyst call for it to be in a dried, powder form. Strike supposes the benzene in the above reaction can be distilled off to leave dry catalyst. But don t quote Strike on that Maybe it could be made in situ in the DCE solvent of the reaction to come (don t ask). Aw hell Just go and buy the shit ... [Pg.121]

Using a standard vacuum distillation the solvent is distilled off. This shouldn t take too long. The first thing to come over after the solvent was the safrole, which with my vacuum (2mm) started at around 9CfC. The safrole will be a clear liquid, slightly viscous and will smell of liquorice. With the above measurements one can expect a yield of around 85g. No further cleaning up is necessary, and the safrole can be used as is for any further reactions. ... [Pg.237]

To a solution of 0.35 mol of allenyllithium in 240 ml of hexane and 200 ml of THF (see Chapter II, Exp. 13) were added 25 g of dry HMPT at -80°C. Subsequently 0.30 mol of l-bromo-3-chloropropane were added in 10 min. The reaction was very exothermic, but could be kept under control by occasional cooling in a bath with liquid nitrogen. After an additional 10 min the cooling bath was removed and the temperature was allowed to rise to -30°C. The solution was then poured into 500 ml of water. The organic layer and three ethereal extracts were dried over magnesium sulfate. The solvents were distilled off as thoroughly as possible at... [Pg.30]

In a similar way H2C=C=CH-SC2H5, b.p. 30 c/12 nmHg, n 1.5210, was prepared in 864 yield from CH3C=C-SC2H5. After the greater part of the solvent had been distilled off at normal pressure (bath temperature below 70°C), the remaining liquid was distilled at water-pump pressure and collected in a single receiver... [Pg.108]


See other pages where Distilling off solvents is mentioned: [Pg.278]    [Pg.1265]    [Pg.279]    [Pg.31]    [Pg.163]    [Pg.163]    [Pg.278]    [Pg.1265]    [Pg.279]    [Pg.31]    [Pg.163]    [Pg.163]    [Pg.171]    [Pg.163]    [Pg.288]    [Pg.567]    [Pg.816]    [Pg.832]    [Pg.850]    [Pg.895]    [Pg.913]    [Pg.917]    [Pg.941]    [Pg.978]    [Pg.115]    [Pg.158]    [Pg.215]    [Pg.28]    [Pg.37]    [Pg.41]    [Pg.42]    [Pg.48]    [Pg.57]    [Pg.72]    [Pg.84]   
See also in sourсe #XX -- [ Pg.21 ]

See also in sourсe #XX -- [ Pg.21 ]




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Distillation solvent

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