Abietic acid, acid sodium salt


It is now necessary to place about i g. of finely powdered pure silver nitrate in the closed end of the tube at the same time, care should be taken to avoid dusting the internal walls of the tube with silver nitrate, as it is a great advantage to have the silver halide subsequently collected at the extreme end of the tube, and not scattered in specks over the walls. Therefore roll a narrow strip of clean glazed paper around the quill-tubing originally used for drying the tube and then insert the roll of paper and the quill-tube into the Carius tube (which has been clamped in a vertical position) until the paper roll reaches within about 5 cm. of the bottom of the Carius tube. Now remove the central quill-tube, when the paper will tend to unroll slightly and so grip the Carius tube securely. Add about i g. of the powdered silver nitrate, tap the tube to shake down the last fragments of the nitrate, and then withdraw the paper roll. Insert into the tube a clean thistle-funnel, the stem of which has been extended until it reaches to about 10 cm. from the bottom of the tube. Add i -z-o ml. (not more) of fuming nitric acid (d, 1-5) for this and the next estimation, a sample of fuming nitric acid free from halogen and sulphur should be used. If there is any doubt with regard to the purity of the acid, the latter should be well shaken with a small quantity of powdered silver nitrate, and the mixture allowed to stand (preferably overnight) until all the solid matter has collected at the bottom, the acid being subsequently withdrawn for the analysis by means of a short dropping-tube. When the nitric acid has thoroughly drained from the thistle-funnel, the latter should be cautiously withdrawn so that the upper portion of the Carius tube is not wetted.  [c.418]

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.  [c.1077]

It is now necessary to place about i g. of finely powdered pure silver nitrate in the closed end of the tube at the same time, care should be taken to avoid dusting the internal walls of the tube with silver nitrate, as it is a great advantage to have the silver halide subsequently collected at the extreme end of the tube, and not scattered in specks over the walls. Therefore roll a narrow strip of clean glazed paper around the quill-tubing originally used for drying the tube and then insert the roll of paper and the quill-tube into the Carius tube (which has been clamped in a vertical position) until the paper roll reaches within about 5 cm. of the bottom of the Carius tube. Now remove the central quill-tube, when the paper will tend to unroll slightly and so grip the Carius tube securely. Add about i g. of the powdered silver nitrate, tap the tube to shake down the last fragments of the nitrate, and then withdraw the paper roll. Insert into the tube a clean thistle-funnel, the stem of which has been extended until it reaches to about 10 cm. from the bottom of the tube. Add i-5-2-o ml. not more) of fuming nitric acid d, 1-5) for this and the next estimation, a sample of fuming nitric acid free from halogen and sulphur should be used. If there is any doubt with regard to the purity of the acid, the latter should be well shaken with a small quantity of powdered silver nitrate, and the mixture allowed to stand (preferably overnight) until all the solid matter has collected at the bottom, the acid being subsequently withdrawn for the analysis by means of a short dropping-tube. When the nitric acid has thoroughly drained from the thistle-funnel, the latter should be cautiously withdrawn so that the upper portion of the Carius tube is not wetted.  [c.418]

Place 20 ml. (21 g.) of benzaldehyde (freshly distilled to ensure absence of benzoic acid), 30 ml. of acetic anhydride, and tog. of finely powdered anhydrous sodium acetate in a 100 ml. round-bottomed flask fitted with a water-condenser closed at the top by means of a calcium chloride tube bent downwards cf. Fig. 61, p. 105). Now heat the flask in an oil-bath at 175-180° for 8 hours the mixture boils vigorously under reflux and white particles separate in the liquid. Pour the mixture whilst still hot into 100 ml. of water contained in a round-bottomed flask (of about I litre capacity) which has previously been fitted for steam-distillation. Now add with vigorous shaking a saturated aqueous solution of sodium carbonate until a drop of the liquid withdrawn on a rod turns red litmus-paper a distinct blue. (Sodium hydroxide must not be used for this purpose, as it may generate benzoic acid by the Cannizzaro reaction from any unchanged benzaldehyde.) Now steam-distil the solution until unchanged benzaldehyde has been removed and the distillate is no longer turbid. Cool the residual solution until the small quantity of insoluble oily impurity has formed a semi-solid sticky mass, and then filter at the pump. Acidify the clear filtrate by adding concentrated hydrochloric acid cautiously with vigorous stirring until the evolution of carbon dioxide ceases and the precipitation of cinnamic acid is complete. Cool if necessary in ice-water, and then filter off the cinnamic acid, wash thoroughly with water, and drain. Recrystallise from a mixture of 3 volumes of water and i volume of rectified spirit yield, 18 g. Cinnamic acid is thus obtained as colourless crystals, m.p. 133° it has a faint and pleasant odour and is almost insoluble in cold water.  [c.237]

Dissolve 13 g. of sodium in 30 ml. of absolute ethanol in a 250 ml. flask carrying a reflux condenser, then add 10 g. (9 5 ml.) of redistilled ethyl malonate, and place the flask on a boiling water-bath. Without delay, add a solution of 5 3 g. of thiourea in a minimum of boiling absolute ethanol (about 100 ml.). The sodium salt of thiobarbituric acid rapidly begins to separate. Fit the water-condenser with a calcium chloride guard-tube (Fig. 61, p. 105), and boil the mixture on the water-bath for 1 hour. Cool the mixture, filter off the sodium salt at the pump and wash it with a small quantity of cold acetone. Dissolve the salt in warm water and liberate the acid by the addition of 30 ml. of concentrated hydrochloric acid diluted with 30 ml. of water. Cool the mixture, filter off the thiobarbituric acid, and recrystallise it from hot water. Colourless crystals, m.p. 245 with decomposition (immersed at 230°). Yield, 3 5 -4 0 g.  [c.307]

Example. Dissolve 0 3 g. of benzoic acid in a minimum of hot water (about 70 ml.) and add 5% aqueous sodium hydro.xide until the solution is just alkaline to methyl-orange, then add i drop of dilute hydrochloric acid. Pour this solution of the sodium salt into a solution of 0 5 g, of benzylthiouronium chloride in 5 ml. of water, and cool the stirred mixture in ice-water. Filter off the benzylthiouronium salt which has separated, and recrystallise from ethanol con taining 10% of water cream-coloured cr> stals, m.p. i66 . (M.ps., pp. 543 545.)  [c.349]

P-Hydroxy-a-naphthaldehyde, Equip a 1 litre three-necked flask with a separatory funnel, a mercury-sealed mechanical stirrer, and a long (double surface) reflux condenser. Place 50 g. of p-naphthol and 150 ml. of rectified spirit in the flask, start the stirrer, and rapidly add a solution of 100 g. of sodium hydroxide in 210 ml. of water. Heat the resulting solution to 70-80° on a water bath, and place 62 g. (42 ml.) of pure chloroform in the separatory funnel. Introduce the chloroform dropwise until reaction commences (indicated by the formation of a deep blue colour), remove the water bath, and continue the addition of the chloroform at such a rate that the mixture refluxes gently (about 1 5 hours). The sodium salt of the phenolic aldehyde separates near the end of the addition. Continue the stirring for a further 1 hour. Distil off the excess of chloroform and alcohol on a water bath use the apparatus shown in Fig. II, 41, 1, but retain the stirrer in the central aperture. Treat the residue, with stirring, dropwise with concentrated hydrochloric acid until  [c.704]

Equip a 1500 ml. three-necked flask with a thermometer, mechanical stirrer and a dropping funnel. Place 61 g. (54 ml.) of nitromethane (Section 111,55), 106 g (101 ml.) of purified benzaldehyde (Section IV,115) and 200 ml. of methanol in the flask and cool it with a mixture of ice and salt to about —10°. Dissolve 42 g. of sodium hydroxide in 40-50 ml, of water, cool and dilute to 100 ml, with ice and water place this cold solution in the dropping funnel. Add the sodium hydroxide solution, with vigorous stirring, to the nitromethane mixture at such a rate that the temperature is held at 10-15°. Introduce the first few ml. cautiously since, after a short induction period, the temperature may rise to 30° or higher check the rise in temperature, if necessary, by adding a little crushed ice to the reaction mixture. A bulky white precipitate forms if the mixture becomes so thick that stirring is difficult, add about 10 ml. of methanol. After standing for about 15 minutes, add 700 ml. of ice water containing crushed ice the temperature should be below 5°. Run the resulting cold solution immediately from a dropping funnel and with stirring into 500 ml. of 2 3-hydrochloric acid contained in a 3-htre flask or jar adjust the rate of addition so that the stream just fails to break into drops. A pale yellow crystalline precipitate separates almost as soon as the alkaline solution mixes with the acid. The solid settles to the bottom of the vessel when the stirrer is stopped. Decant most of the cloudy liquid layer, filter the residue by suction and wash it with water until free from chlorides. Transfer the solid to a beaker immersed in hot water two layers form and on cooling again, the lower layer of nitro-styrene solidifies pour off the upper water layer. Dissolve the crude nitrostyrene in 85 ml. of hot ethanol (FUME CUPBOARD nitrostyrene vapours are irritating to the nose and eyes, and the skin of the face is sensitive to the solid), filter through a hot water funnel and cool until  [c.717]

Dissolve 1-3 g. of sodium in 30 ml. of absolute ethanol in a 250 ml. flask carrying a reflux condenser, then add 10 g. (9-5 ml.) of redistilled ethyl malonate, and place the flask on a boiling water-bath. Without delay, add a solution of 5 3 g. of thiourea in a minimum of boiling absolute ethanol (about too ml.). The sodium salt of thiobarbituric acid rapidly begins to separate. Fit the water-condenser with a calcium chloride guard-tube (Fig. 61, p. 105), and boil the mixture on the water-bath for 1 hour. Cool the mixture, filter off the sodium salt at the pump and wash it with a small quantity of cold acetone. Dissolve the salt in warm water and liberate the acid by the addition of 30 ml. of concentrated hydrochloric acid diluted with 30 ml. of water. Cool the mixture, filter off the thiobarbituric acid, and recrystallise it from hot water. Colourless crystals, m.p. 245° with decomposition (immersed at 230°). Yield, 3 5-4 0 g.  [c.307]

Example. Dissolve 0 3 g. of benzoic acid in a minimum of hot water (about 70 ml.) and add 5% aqueous sodium hydro.xide until the solution is just alkaline to methyl-orange, then add i drop of dilute hydrochloric acid. Pour this solution of the sodium salt into a solution of 0 5 g. of benzylthiouronium chloride in 5 ml. of water, and cool the stirred mixture in ice-water. Filter off the benzylthiouronium salt which has separated, and recrystallise from ethanol containing 10% of water cream-coloured ciystals, m.p. 166°. (M.ps., pp. 543 -545.)  [c.349]

Other Sta.bilizers. In addition to anionic, cationic, and nonionic surfactants used in manufacture of the latex, other specialized surfactants can be added or compounded to the latex after manufacture to increase the stabiHty of the latex. For example, amphoteric surfactants like i -cetyl betaine are used to improve the mechanical stabiHty of low pH anionic compounds. Quaternary ammonium salts are used to improve the mechanical stabiHty of cationic latices and their compounds. They are used either alone or in combination with a nonionic surfactant. Sequestrants (91) such as sodium siHcate, sodium polyphosphate, and the sodium salt of ethylene diamine tetraacetic acid are added to anionic latices to retard the destabilizing action of cations that get leached slowly from compounding ingredients containing multivalent ions. The addition of these ingredients is also beneficial if the use of hard water is unavoidable in making and using the anionic latex compound. Care must be taken to avoid shocking the latex during compounding with these additional surfactants.  [c.27]

Kraft Lignins. Kraft lignins, also called sulfate or alkali lignins, are obtained from black hquor by precipitation with acid. Generally, acidification is conducted in two steps. In the first step, carbon dioxide from the waste gases of boiler fires or from lime kilns is used to reduce the pH of the hquor from 12 to 9—10. About three quarters of the lignin is precipitated in this step as a sodium salt. After isolation, the material thus obtained can be used as is or further refined by washing. By suspending the salt in water and lowering the pH to 3 or less with sulfuric acid, refined lignin is obtained.  [c.145]

The kiln discharge is leached with water, resulting in an impure lithium sulfate solution that contains the excess sulfuric acid and small amounts of aluminum, iron, and other alkaU sulfates. The excess sulfuric acid is neutralized with ground limestone. The slurry is then filtered to separate the ore residue, giving a mixed alkaU sulfate solution that is free of iron and aluminum but that is saturated with calcium sulfate. The solution also contains magnesium ions derived mainly from the limestone. Magnesium is precipitated using hydrated lime, followed by precipitation of calcium using soda ash or mother Hquor containing sodium carbonate generated in subsequent precipitation of by-product sodium sulfate decahydrate. After filtration, the solution is adjusted using sulfuric acid to pH 7—8, followed by concentration in a multiple-effect evaporator to alkah sulfate concentration of 350 g/L, 200—250 g/L of this being lithium sulfate. After a clarifying filtration, lithium carbonate is precipitated at 90—100°C with a 28 wt % soda ash solution. The precipitated lithium carbonate is centrifuged, washed, and dried. Approximately 15% of the lithium remains in the mother Hquor, along with residual sodium carbonate and large amounts of sodium sulfate. Cooling to about 0°C separates the greater part of the sodium sulfate as the decahydrate, which is centrifuged and converted to the anhydrous salt for by-product sale. The mother Hquor from the sodium sulfate decahydrate precipitation is recycled for lithium and soda ash values.  [c.222]

Benzene SuIfona.tion. In the benzene sulfonation process, benzene reacts with concentrated sulfuric acid to form benzenesulfonic acid at about 150°C. The benzenesulfonic acid is neutralized with sodium sulfate to produce sodium benzenesulfonate, which is then fused with caustic soda to yield sodium phenate. The sodium phenate is acidified with sulfur dioxide and a small amount of sulfuric acid to release the phenol from the sodium salt. The phenol yield by this process can be as high as 88 mol % to that of the theoretical value based on benzene. Plants employing this technology have been shut down for environmental and economic reasons.  [c.289]

Benzene Chlorination. In this process, benzene is chlorinated at 38—60°C in the presence of ferric chloride catalyst. The chlorobenzene is hydrolyzed with caustic soda at 400°C and 2.56 kPa (260 atm) to form sodium phenate. The impure sodium phenate reacts with hydrochloric acid to release the phenol from the sodium salt. The yield of phenol is about 82 mol % to that of the theoretical value based on benzene. Plants employing this technology have been shut down for environmental and economic reasons.  [c.289]

Although not as corrosive as the acid, the sodium and potassium salts of citric acid should be handled in the same type of equipment as the acid to avoid corrosion problems.  [c.184]

In processing articles, after degreasing in trichloroethylene vapour or elec-trolytically in a hot alkaline solution, e.g. 25 g/1 trisodium phosphate and 12.5 g/1 sodium carbonate at 80-90°C, they are pickled in 50% v/v hydrochloric acid at ambient temperature or 5-10% v/v sulphuric acid and rinsed. The surface of cast iron is often contaminated with sand from the casting process and normal pickling processes cannot deal with this. The addition of some HF to a sulphuric acid bath helps to remove a siliceous skin. Making the pickling process more severe or more prolonged often makes matters worse because the sludge and smut left on the surface by the pickling action are increased. The simplest cleaning method is by hne grit blasting after which the iron may be fluxed and tinned directly. Tinning trouble due to graphite may be overcome by rough mechanical cleaning followed by elec-trodepositing a thin coating of iron or copper. Alternatively, the graphite may be removed, either by surface decarburisation (as in malleable cast iron) or by treatment in molten salt baths, e.g. equal parts of sodium and potassium nitrates. The nitrate salts are then washed off and the article is lightly pickled, rinsed and fluxed in the usual way, e.g. by dipping in an aqueous flux solution containing, for example, 240g/1 zinc chloride, 60 g/1 sodium chloride, 30 g/1 ammonium chloride and 6-12 ml/1 hydrochloric acid (sp. gr. 1.14). The articles, wet with flux solution, are lowered carefully into a bath of molten tin (at about 280°C) having a layer of fused flux floating on it and covering about two-thirds of its surface. The flux cover is composed of a mixture of dry chlorides in the same proportions by weight as in the flux solution being carried over with the work. Thus, in the example given, finely ground zinc, sodium and ammonium chlorides are mixed in the proportions 8 2 1 to form the flux blanket.  [c.390]

Dissolve 4 5 ml. of aniline in a mixture of 10 ml. of concentrated hydrochloric acid and 20 ml. of water cool the solution to 5°, and diazotise by the addition of 4 g. of sodium nitrite dissolved in 20 ml, of water, observing the usual precautions given on page 181. Dissolve 7 g. of 2-naphthol in 60 ml. of 10% sodium hydroxide solution contained in a 200 ml. beaker, and cool this solution to 5 by external cooling, aided by the direct addition of about 20-30 g. of crushed ice. Now add the diazotised solution very slowly to the naphthol solution, keeping the latter well stirred meanwhile the mixed solutions immediately develop a deep red colour, and the benzeneazonaphthol should  [c.210]

Remove the shells from i g. of the seeds (about 5) and then grind up the latter thoroughly in a mortar. Add a few ml. of water and work into a paste. Proceed in this way adding a few ml. at a time until in all 25 ml. of water have been added. If this has been done thoroughly, a cream of uniform consistency will be obtained. Using a small measuring-cylinder, transfer 10 ml. of the lipase cream to each of two boiling-tubes A and B. Then using a 1 ml. pipette, add exactly 1 ml. of M 10 aatic acid to each and mix well this activates the enzyme. Boil the contents of B for 2 minutes in order to destroy the enzyme, then place both tubes in a water-bath maintained at 40°, shaking well frcm time to time. After 45 minutes remove the tubes, cool, add 2 drops of phenolphthalein to each and titrate with il/ 10 sodium hydroxide solution. It will be found that more alkali is required to neutralise the acid in A than in B, showing that acid has been produced by enzymatic hydrolysis. An interesting feature, usually observable in the titration of A, is that when the end-point is approached the suspension becomes almost clear. This is due to the fact that the ester of the seeds has been hydrolysed to a fatty acid and an alcohol. The insoluble fatty acid is gradually replaced by its soluble sodium salt as the titration proceeds. The contents of B will of course remain cloudy.  [c.512]

Fit a 1000 ml. three-necked flask with a mechanical stirrer not mercury sealed), a dropping funnel (Fig. II, 1, 5,f) with stem reaching to almost the bottom of the flask, and another separatory funnel but with a short stem. Clamp the flask in a large beaker containing water maintained at 50°. Introduce into the flask 30 ml. (24 g.) of acetone and 150 ml. of 20 per cent, sodium carbonate solution. Place 76 ml. (234 g.) of bromine in the long-stemmed funnel and 10 per cent, sodium hydroxide solution in the other funnel (about 800 ml. are required). Set the stirrer in motion and allow the bromine to drop slowly into the well-stirred alkaline mixture. Bromoform soon separates out. As soon as the bromine is no longer decolourised, introduce the sodium hydroxide solution from the second separatory funnel slowly and at such a rate that the mixture in the flask does not become strongly alkaline. The correct rate of addition of the sodium hydroxide solution is attained when, on stopping the addition, the liquid immediately assumes the red colour of bromine. The bath should be maintained at 50° throughout the experiment. When all the bromine has been introduced, stop the addition of the alkali, remove the heavy layer of bromoform, wash it with water, and dry with anhydrous calcium chloride. (If desired, the dry bromoform may be shaken with concentrated sulphuric acid to remove impurities, but this is not always necessary.) Distil the crude bromoform, preferably in a current of carbon dioxide, and collect the fraction boiling at 148-149 -5° this has a m.p. of 7-8°. The yield is 68 g.  [c.299]

In a 500 ml. bolt-head flask, provided with a mechanical stirrer, place 70 ml. of oleum (20 per cent. SO3) and heat it in an oil bath to 70°. By means of a separatory funnel, supported so that the stem is just above the surface of the acid, introduce 41 g. (34 ml.) of nitrobenzene slowly and at such a rate that the temperature of the well-stirred mixture does not rise above 100-105°. When all the nitrobenzene has been introduced, continue the heating at 110-115° for 30 minutes. Remove a test portion and add it to the excess of water. If the odour of nitrobenzene is still apparent, add a further 10 ml. of fuming sulphuric acid, and heat at 110-115° for 15 minutes the reaction mixture should then be free from nitrobenzene. Allow the mixture to cool and pour it with good mechanical stirring on to 200 g. of finely-crushed ice contained in a beaker. AU the nitrobenzenesulphonic acid passes into solution if a little sulphone is present, remove this by filtration. Stir the solution mechanically and add 70 g. of sodium chloride in small portions the sodium salt of m-nitro-benzenesulphonic acid separates as a pasty mass. Continue the stirring for about 30 minutes, allow to stand overnight, filter and press the cake well. The latter will retain sufficient acid to render unnecessary the addition of acid in the subsequent reduction with iron. Spread upon filter paper to dry partially.  [c.589]

Place 84 g. of iron filings and 340 ml. of water in a 1 - 5 or 2-litre bolt-head flask equipped with a mechanical stirrer. Heat the mixture to boiling, stir mechanically, and add the sodium m-nitrobenzenesulphonate in small portions during 1 hour. After each addition the mixture foams extensively a wet cloth should be applied to the neck of the flask if the mixture tends to froth over the sides. Replace from time to time the water which has evaporated so that the volume is approximately constant. When all the sodium salt has been introduced, boU the mixture for 20 minutes. Place a small drop of the suspension upon filter paper and observe the colour of the spot it should be a pale brown but not deep brown or deep yellow. If it is not appreciably coloured, add anhydrous sodium carbonate cautiously, stirring the mixture, until red litmus paper is turned blue and a test drop upon filter paper is not blackened by sodium sulphide solution. Filter at the pump and wash well with hot water. Concentrate the filtrate to about 200 ml., acidify with concentrated hydrochloric acid to Congo red, and allow to cool. Filter off the metanilic acid and dry upon filter paper. A further small quantity may be obtained by concentrating the mother liquid. The yield is 55 g.  [c.589]

Dissolve 9-3 g. (91 ml.) of aniline in a mixture of 19.6 g, (10-7 ml.) of concentrated sulphuric acid and 100 ml. of water, and cool to about 5°. Diazotise by the addition of a solution of 7 0 g. of sodium nitrite in 15 ml. of water to an end point with potassium iodide - starch paper maintain the temperature below 10°. Add an ice-cold mixture of 40 g. (22 ml.) of concentrated sulphuric acid and 30 ml. of water, cool in ice and pass sulphur dioxide into the solution until there is no further increase in weight (about 25 g.). The solution should not develop any appreciable colour, during this operation and should remain quite clear. When the solution is saturated with sulphur dioxide, transfer it to a beaker provided with a mechanical stirrer, and add copper powder (Section 11,50, 4) or copper bronze (previously washed with ether) gradually until no more nitrogen is evolved (about 50 g. of copper powder are required). Filter at the pump and wash the precipitate with several small amounts of dilute ammonia solution to remove any sulphinic acid which may have separated add the washings to the filtrate. The combined filtrate and washings should be acid to Congo red paper. Treat it with concentrated ferric chloride solution as long as any precipitate forms. Filter the precipitate of ferric benzenesulphinate, and wash it with a httle water. Decompose the ferric salt with a shght excess of 5 per cent, sodium hydroxide solution, and filter the precipitated ferric hydroxide. Acidify the filtrate and extract the sulphinic acid with ether. Upon evaporation of the solvent, pure benzenesulphinic acid, m.p. 84°, is obtained as a colourless crystaUine solid. The yield is 10 g. It oxidises in the air.  [c.607]

Add 49 g. (27 ml.) of concentrated sulphuric acid cautiously and with stirring to 200 ml. of water in a 1 litre round-bottomed flask, and to the resulting hot solution add 23 g. (22 -5 ml.) of aniline warm the mixture gently until all the aniline dissolves. Add 200 ml. of cold water and cool the mixture in ice until the temperature falls below 5°. During the cooling process, keep the mixture well shaken. This will ensure that any aniline sulphate which separates will be in a finely-divided crystalline form this dissolves rapidly as the diazotisation proceeds. Add a cold solution of 18 g. of sodium nitrite in 35 ml. of water slowly and with constant shaking to an end point with potassium iodide - starch paper follow the precautions given under lodobenzene. Section IV,60. When all the sodium nitrite solution has been introduced, allow the solution to stand at room temperature for 15-20 minutes to ensure complete diazotisation. Place the flask in a water bath, and heat the latter until the temperature of the diazotised solution reaches 50°. Continue the heating for 15 minutes or until the evolution of nitrogen ceases, taking care that the temperature of the solution does not exceed 55°. Steam distil (see Vig. 11,40, 1) the reaction mixture until 400 ml. of distillate are collected. Transfer the distillate to a separatory funnel, add about 20 g. of salt and  [c.613]

In the meantime, prepare a sodium sulphite solution as follows. In a 2-litre beaker or bolt-head flask place 50 g. of sodium hydroxide (2) and add 500 ml. of water. When the sodium hydroxide has dissolved, add 112-5 g. of recrystallised sodium bisulphite (3), and stir mechanically until the solid has dissolved. Cool the resulting solution to about 25° and add a few drops of phenolphthalein indicator solution. Introduce small quantities of sodium bisulphite until the pink colour of the solution just disappears, then stir in a further 12 g. of sodium bisulphite (the total weight required should not exceed 135-140 g.). Cool this solution, with stirring, to about 5° by immersion in an ice bath, then add about 60 g. of crushed ice. Run in the ice-cold diazonium solution as rapidly as possible, while stirring vigorously. The reaction mixture immediately acquires a bright orange-red colour. Slowly heat the solution to 60-70 on a water bath and maintain this temperature for 30-60 minutes, i.e., until the colour becomes quite dark. Acidify the solution to litmus with concentrated hydrochloric acid (40-50 ml. are required) continue the heating on a boiling water bath until the colour becomes much hghter and in any case for 4-6 hours. If any solid is present, filter the solution. To the hot, clear solution add, with stirring, 500 ml. of concentrated hydrochloric acid cool, first in running water, and then in a freezing mixture to 0°. The phenylhydrazine hydrochloride separates as yellowish or pinkish crystals. CoUect them on a Buchner funnel, drain, wash with 25 ml. of dilute hydrochloric acid (1 3), and press well with a large glass stopper (4).  [c.636]

In a 500 ml. flask, fitted with a reflux condenser, place 53 g. of 1-chloro-methylnaphthalene (Section IV.23), 84 g, of hexamethylenetetramine and 250 ml. of 1 1 acetic acid [CAUTION 1-Chloromethylnaphtha-lene and, to a lesser degree, a-naphthaldehyde have lachrymatory and vesicant properties adequate precautions should therefore be taken to avoid contact with these substances.] Heat the mixture under reflux for 2 hours it becomes homogeneous after about 15 minutes and then an oil commences to separate. Add 100 ml. of concentrated hydrochloric acid and reflux for a further 15 minutes this will hydrolyse any SchifiF s bases which may be formed from amine and aldehyde present and will also convert any amines into the ether-insoluble hydrochlorides. Cool, and extract the mixture with 150 ml. of ether. Wash the ether layer with three 50 ml. portions of water, then cautiously with 50 ml. of 10 per cent, sodium carbonate solution, followed by 50 ml. of water. Dry the ethereal solution with anhydrous magnesium sulphate, remove the ether by distillation on a steam bath, and distil the residue under reduced pressure. Collect the a-naphthaldehyde at 160-162718 mm. the yield is 38 g.  [c.700]

Into a 750 ml. wide-mouthed bottle, provided with a mechanical stirrer, place a solution of 25 g. of technical sodium cyanide (97-98 per cent. NaCN) in 100 ml. of water and 53 g. (51 ml.) of purified benzaldehyde (Section IV, 115). Prepare a saturated solution of sodium bisulphite by stirring 250 g. of finely-powdered technical sodium bisulphite with 335 ml. of water and filtering to remove the excess of the salt. Stir the mixture in the bottle and add the sodium bisulphite solution slowly at first and then more rapidly (the addition occupies 10-15 minutes). During the addition of the first half of the solution, add 150 g. of crushed ice to the reaction mixture in several portions. Transfer the product to a separatory funnel and remove the layer of crude mandelonitrile (1). Place the latter at once (2) in a large evaporating dish, add 75 ml. of concentrated hydrochloric acid, cover with a clock glass, and allow the hydrolysis to proceed in the cold for 12 hours finally evaporate to dryness on a water bath. Grind the residue of slightly discoloured mandelic acid and inorganic salts to a fine powder in a mortar and wash it twice with 125 ml. portions of cold benzene this process will remove most of the colouring matter and a negligible quantity of mandelic acid. To separate inorganic salts from the mandehc acid, extract the residue in a Soxhlet apparatus (Figs. 11,44, 4-6) with about 200 ml. of benzene on a water bath. Allow the hot benzene extract to crystallise, collect the crystals on a Buchner funnel and dry in the air. The yield of pure dZ-mandelic acid, m.p. 118°, is 35 g.  [c.774]

To prepare the free sulphinic acid, dissolve some of the sodium salt in cold water and cautiously acidify with hydrochloric acid avoid an excess of mineral acid since it dissolves the sulphinic acid to a certain extent. The resulting p-tolueneaulphinic acid is difflcult to dry without partial conversion into the sulphonic acid and thiolsulphonic ester  [c.826]

In a 1500 ml. tluee-necked flask, fitted with a dropping funnel and a liquid sealed mechanical stirrer, place 195 g. (190 ml.) of ethyl acetoacetate (Section 111,151) and 450 ml. of glacial acetic acid. Cool the solution in an ice-salt mixture to 5° add a cold solution of 52 g. of A.R. sodium nitrite in 76 ml. of water dropwise and with vigorous stirring at such a rate that the temperature remains between 5° and 7 (about 30 minutes) stir for a further 30 minutes, and keep at room temperature for 4 hours. Replace the dropping funnel by a wide-bore condenser close the third neck with a stopper. Stir the solution vigorously and add 100 g. of zinc powder (of purity < 80 per cent. the weight given is for 100 per cent, material) in portions of about 10 g. introduce the first 3 or 4 portions quickly so that the liquid i.s kept boiling. Keep a hath of ice water and also wet towels at hand to control the reaction should it become violent or foam badly. When all the zinc has been added (about 45 minutes), reflux the mi ure for 1 hour if stirring becomes difficult, add some acetic acid. While still hot, decant the contents of the flask into 5 litres of water vigorously stirred in a crock. Wash the zinc residue with two 25 ml. portions of hot glacial acetic acid and decant these into the water also. Keep overnight, collect the crude product by suction filtration, wash with two 260 ml. portions of water, and dry in the air to constant weight. The yield of crude product is 114 g., m.p. 127-130°. Recrystalhsation from hot 95 per cent, ethanol gives pure 2 4-dimethyl-3 5-dicarh-ethoxypyrrole as pale j ellow crystals, m.p. 136-137° the recovery is about 80 per cent.  [c.839]

Fit the 3 litre three-necked flask used in the original oxidation with a thermometer, a glycerine sealed stirrer (Fig. U, 7, 10), and a large automatic water separator (ca. 200 ml. capacity see Fig. Ill, 126, 1) surmounted by a double surface reflux condenser. Support a small funnel upon three indentations immediately above the side tube of the water-separator its stem should be well below the side tube so that liquid falling from the condenser cannot splash over into the flask. Transfer the solution to the flask and add 1500 ml. of benzene heat on a water bath at 90° and stir vigorously. Continue the refluxing and stirring until no more water collects in the trap (about 12 hours). Filter the hot benzene solution through a hot water funnel and evaporate to dryness on a boiling water bath. Evaporation is best carried out under reduced pressure (water pump) since this leads to an almost colourless acid and most of the benzene is recovered the apparatus may consist of a 2 litre bolt-head flask, still head, double surface condenser and receiver. Return the recovered benzene to the extraction flask, stir and extract the residual solid at the temperature of a boiling water bath for a further 2 hours evaporate the benzene extract under reduced pressure and thus obtain a second crop of picolinic acid. Carry out a third extraction with the benzene recovered  [c.847]

Aluminium tert.-butoxide. In a 500 ml. louiid-bottomed ilask fitted with a reflux condenser protected by a calcium chloride or cotton wool tube, place 16 g. of aluminium turnings, 50 g. (63 5 ml.) of anhydrous fert.-butyl alcohol and 2 g. of aluminium isopropoxide (Section VI,12 to remove traces of water). Heat the mixture to boiling on a steam bath, add about 0 -1 g. of mercuric chloride and shake vigorously the object of the shaking is to distribute the mercuric chloride and thus assist an even amalgamation of the aluminium. Continue the heating on the steam bath the colour of the reaction mixture gradually changes from clear to milky to black and hydrogen is evolved. Remove the flask from the steam bath when the mixture is black, allow the reaction to proceed for an hour, and then add 61 g. (77 ml.) of anhydrous butyl alcohol and 50 ml. of anhydrous benzene. Heat gently to restart the reaction it will continue vigorously without further heating for about 2 hours when the reaction subsides, reflux the mixture for 12 hours. Remove the benzene and unreacted [c.887]

In a 500 ml. three-necked flask, supported on a water bath and provided with a dropping funnel, a mechanical stirrer and a thermometer, place 72 g. (90 ml.) of redistilled methyl ethyl ketone (dried over anhydrous magnesium or copper sulphate). Start the stirrer, introduce 3 ml. of concentrated hydrochloric acid and waim the liquid to 40°. Then add 100 g. (112 ml.) of re-butyl nitrite (b.p. 76-79°) or 112 g. (129 ml.) of tso-amyl nitrite (b.p. 96-99°) (Section 111,53) slowly, maintaining the temperature at 40-50° the mixture must be stirred vigorously. Heat is generated in the reaction so that cooling may now be required. Continue the stirring, without coohng, for 30 minutes after all the nitrite has been added. The reaction mixture now consists of a solution of diacetyl monoxime in re-butyl or wo-amyl alcohol. To remove any unused ketone, treat the mixture with a cold solution of 45 g. of sodium hydroxide in 100 ml. of water and stir for 20-30 minutes. Transfer the reaction mixture to a separatory funnel and extract the reddish-brown solution twice with 50 ml. portions of ether the alcohol may be recovered, if desired, by fractionation of the ethereal extracts. Keep the aqueous layer it contains the sodium salt of diacetyl monoxime. Prepare a solution of 70 g. of hydroxylamine hydrochloride NH OH.HCl or of 82 g. of hydroxylamine sulphate (NH20H)2,H2S04) in about three times its weight of water, and add sodium hydroxide solution until the solution is neutral to litmus. Place the aqueous solution of the sodium salt of diacetyl monoxime in a 1 litre bolt-head flask and add the hydroxylamine solution with stirring. Heat the mixture on a water bath for about 45 minutes. Filter off the precipitated dimethylglyoxime (1) whilst the solution is still hot, wash it with hot water, and drain well. Recrystallise the crude product from about 10 times its weight of rectified spirit. The yield of pure dimethylglyoxime (a white, crystalline solid, m.p. 240°) is 55 g.  [c.953]

Dissolve 9 -2 g. of benzidine (Section IV,88) in a hot mixture of 24 ml. of concentrated hydrochloric acid and 150-200 ml. of water. Cool in an ice bath to 0-5° and diazotise ( tetrazotise ) by the addition of a solution of 6-9 g. of sodium nitrite (100 per cent. if the purity is lower, the weight must be adjusted accordingly) in 50 ml. of water within 1 minute. Leave the tetrazo solution in ice for 5 minutes and then add it to a solution of 32 g. of sodium naphthionate (Section IV,56) and 40 g. of crystallised sodium acetate in 500 ml. of water. Stir well and allow the mixture to stand for 1 hour. When a sample of the liquid, upon warming with hydrochloric acid, no longer evolves nitrogen, dissolve the blue-black precipitate of the dye - acid by the gradual addition of sodium carbonate (ca. 20 g.), followed by stirring and warming until the temperature reaches 80°. By this time the dye should be in solution as the red sodium salt (Congo red). Filter, and just saturate (avoid an excess) the hot solution with sodium chloride and allow to cool spontaneously to room temperature. Cool in ice, filter off the Congo red at the pump (1), wash it with saturated sodium chloride solution and dry in the air. The yield is 60 g.  [c.979]

Upon heating anthraquinone with fuming sulphuric acid at 160 for about 1 hour, the main product is anthraquinone-p sulphonic acid, which is isolated as the sparingly soluble sodium salt. The latter when heated under pressure with sodium hydroxide solution and an oxidising agent (sodium or potassium chlorate) yields first the corresponding hydroxy compound further hydroxy-lation occurs in the a-position through oxidation by the chlorate and 1 2-di-hydroxyantliraquinone (alizarin) is formed.  [c.981]

Dissolve 4 5 ml. of aniline in a mixture of 10 ml. of concentrated hydrochloric acid and 20 ml. of water cool the solution to 5°, and diazotise by the addition of 4 g. of sodium nitrite dissolved in 20 ml, of water, observing the usual precautions given on page 181. Dissolve 7 g. of 2-naphthol in 60 ml. of 10% sodium hydroxide solution contained in a 200 ml. beaker, and cool this solution to 5° by external cooling, aided by the direct addition of about 20-30 g. of crushed ice. Now add the diazotised solution very slowly to the naphthol solution, keeping the latter well stirred meanwhile the mixed solutions immediately develop a deep red colour, and the benzeneazonaphthol should rapidly separate as red crystals. If the diazonium solution is added too rapidly, the azo-compound may separate at first as a  [c.210]

Place 20 ml. (21 g.) of benzaldehyde (freshly distilled to ensure absence of benzoic acid), 30 ml, of acetic anhydride, and log. of finelv powdered anhydrous sodium acetate in a 100 ml. round-bottomed flask fitted with a water-condenser closed at the top by means of a calcium chloride tube bent downwards (cf. Fig. 61, p. 105). Now heat the flask in an oil-bath at 175-180° for 8 hours the mixture boils vigorously under reflux and white particles separate in the liquid. Pour the mixture whilst still hot into 100 ml. of water contained in a round-bottomed flask (of about I litre capacity) which has previously been fitted for steam-distillation. Now add with vigorous shaking a saturated aqueous solution of sodium carbonate until a drop of the liquid withdrawn on a rod turns red litmus-paper a distinct blue. (Sodium hydroxide must not be used for this purpose, as it may generate benzoic acid by the Cannizzaro reaction from any unchanged benzaldehyde.) Now steam-distil the solution until unchanged benzaldehyde has been removed and the distillate is no longer turbid. Cool the residual solution until the small quantify of insoluble oily impurity has formed a semi-solid sticky mass, and then filter at the pump. Acidify the clear filtrate by adding concentrated hydrocfiloric acid cautiously with vigorous stirring until the evolution of carbon dioxide ceases and the precipitation of cinnamic acid is complete. Cool if necessary in ice-water, and then filter off the cinnamic acid, wash thoroughly with water, and drain. Recrystallise from a mixture of 3 volumes of water and i volume of rectified spirit yield, 18 g. Cinnamic acid is thus obtained as colourless crystals, m.p. 133° it has a faint and pleasant odour and is almost insoluble in cold water.  [c.237]

Remove the ehelle from i g. of the seeds (about 5) and then grind up the latter thoroughly in a mortar. Add a few ml. of water and work into a paste. Proceed in this way adding a few ml. at a time until in all 25 ml. of water have been added. If this has been done thoroughly, a cream of uniform consistency will be obtained. Using a small measuring-cylinder, transfer 10 ml. of the lipase cream to each of two boiling-tubes A and B. Then using a i ml. pipette, add exactly 1 ml. of M to acetic acid to each and mix well this activates the enzyme. Boil the contents of B for 2 minutes in order to destroy the enzyme, then place both tubes in a water-bath maintained at 40°, shaking well from time to time. After 45 minutes remove the tubes, cool, add 2 drops of phenolphthalein to each and titrate with il/ 10 sodium hydroxide solution. It will be found that more alkali is required to neutralise the acid in A than in B, showing that acid has been produced by enzymatic hydrolysis. An interesting feature, usually observable in the titration of A, is that when the end-point is approached the suspension becomes almost clear. This is due to the fact that the ester of the seeds has been hydrolysed to a fatty acid and an alcohol. The insoluble fatty acid is gradually replaced by its soluble sodium salt as the titration proceeds. The contents of B will of course remain cloudy.  [c.512]

Acesulfame-K is a white crystalline powder having a long (six years or more) shelf life. It readily dissolves in water (270 g/L at 20°C). Like saccharin, acesulfame-K is stable to heat over a wide range of pH. At higher concentrations, there is a detectable bitter and metallic off-taste similar to saccharin. Use of the sodium salt of feruHc acid [437-98-4] (FEMA no. 3812) to reduce the bitter aftertaste of acesulfame-K has been described (64). The sweetness potency of acesulfame-K (100 to 200x, depending on the matching sucrose concentration) (63) is considered to be about half that of saccharin, which is about the same as that of aspartame.  [c.276]

To start the process, appropriate amounts of sulfur and a piae tar resia are dissolved ia chloroprene to make a monomer solution. A water solution is also made up containing sodium hydroxide, and the sodium salt of a naphthalenesulfonic acid—formaldehyde condensation product. The two solutions are emulsified together, giving an oil-ia-water emulsion. A sodium rosiaate emulsifier is formed in situ on mixing of the aqueous and organic solutions. The formaldehyde condensation product is present to coUoidaHy stabilize the latex at the low pH duiing the polymer isolation procedure. Emulsification is achieved by recirculating the two Hquid phases through a centrifugal pump to give a particle size of about 3 p.m. When emulsification is complete, the mixture is pumped to the polymerizer. This is a jacketed, glass-lined reaction vessel having a glass-coated agitator. An aqueous solution of potassium persulfate is added as required to initiate and maintain the polymerization. The temperature is kept at - 40° C by circulating brine through the kettle jacket and by changing the agitator speed.  [c.541]


See pages that mention the term Abietic acid, acid sodium salt : [c.95]    [c.281]    [c.356]    [c.359]    [c.587]    [c.624]    [c.845]    [c.863]    [c.881]    [c.970]    [c.1009]    [c.390]   
Organic syntheses Biclormethyl ether (1956) -- [ c.4 , c.32 ]