With sodium hydroxide solutions

Although carbon monoxide appears to be the anhydride of methanoic acid it does not react with water to give the acid however, it will react with sodium hydroxide solution above 450 K, under pressure, to give sodium methanoate ... 

Carbon disulphide is an excellent solvent for fats, oils, rubber, sulphur, bromine and iodine, and is used industrially as a solvent for extraction. It is also used in the production of viscose silk, when added to wood cellulose impregnated with sodium hydroxide solution, a viscous solution of cellulose xanthate is formed, and this can be extruded through a fine nozzle into acid, which decomposes the xanthate to give a glossy thread of cellulose. 

Reflux Distillation Unit. The apparatus shown in Fig. 38 is a specially designed distillation-unit that can be used for boiling liquids under reflux, followed by distillation. The unit consists of a vertical water-condenser A, the top of which is fused to the side-arm condenser B. The flask C is attached by a cork to A. This apparatus is particularly suitable for the hydrolysis of esters (p. 99) and anilides (p. 109), on a small scale. For example an ester is heated under reflux with sodium hydroxide solution while water is passed through the vertical condenser water is then run out of the vertical condenser and passed through the inclined condenser. The rate of heating is increased and any volatile product will then distil over. 

Dissolve 3-8 g. of sodium in 75 mi. of rectified spirit, using otherwise the same conditions as in the preparation of anisole. Then add 15 g. of phenol, and to the clear solution add 13 2 ml. (19-1 g., n mois.) of ethyl bromide. Continue precisely as in the preparation of anisole, shaking the ethereal extract with sodium hydroxide solution as before in order to eliminate any unchanged phenol. Finally collect the fraction boiling at 168-172°. Yield, 14 g. 

When the sulphon-dichloro-amide is gently boiled with sodium hydroxide solution, the reverse change occurs, and the chloro sodio-amide crystallises out at a suitable concentration ... 

When the reaction has subsided, boil the reaction-mixture under reflux for 2 hours then make it alkaline with sodium hydroxide solution, and distil it in steam until oily drops no longer come over in the aqueous distillate (1 2 litres). Extract the distillate thoroughly with ether ca. 150 ml.), and dry the ethereal extract over powdered sodium hydroxide. Filter the dry extract through a fluted filter-paper moistened with ether into a 200 ml. flask. Fit the flask with a distillation-head, or a knee-tube , and distil off the ether. Now replace the distillation-head by a reflux water-condenser, add 10 ml. of acetic anhydride, and boil the mixture under reflux for 10 15 minutes. 

Dilute sodium hydroxide solution (and also sodium carbonate solution and sodium bicarbonate solution) can be employed for the removal of an organic acid from its solution in an organic solvent, or for the removal of acidic impurities present in a water-insoluble solid or liquid. The extraction is based upon the fact that the sodium salt of the acid is soluble in water or in dilute alkali, but is insoluble in the organic solvent. Similarly, a sparingly soluble phenol, e.g., p-naphthol, CioH,.OH, may be removed from its solution in an organic solvent by treatment with sodium hydroxide solution. 

Commercial n biityl ether is purified by washing with sodium hydroxide solution, water, drying with anhydrous calcium chloride, and then fractionating. The fraction, b.p. 140-142°, is collected. 

Acidify the residue in the flask with dUute sulphuric acid and distil off 10-15 ml. of the solution. Test a smaU portion of the distillate for acidity, and also observe the odour. Neutralise the main portion with sodium hydroxide solution (add a drop of phenolphthalein to act as indicator), evaporate to smaU bulk, and convert the sodium salt into the p-bromophenacyl ester or into some other suitable derivative (Section 111,85) determine the m.p. of the derivative. 

Urea oxalate is also sparingly soluble in amyl alcohol and since urea is soluble in this alcohol, the property may be utilised in separating urea from mixtures. An aqueous extract of the mixture is rendered slightly alkaline with sodium hydroxide solution and extracted with ether this removes all the basic components, but not urea. The residual aqueous solution is extracted with amyl alcohol (to remove the urea) upon adding this extract to a solution of oxalic acid in amyl alcohol crystalline urea oxalate is precipitated. 

ClCHjCHjOH + NaHCOj —> HOCHjCHjOH + COj + NaCl When ethylene chlorohydrin is heated with sodium hydroxide solution, the highly reactive cyclic ether, ethylene oxide, is formed ... 

A better method involves the interaction of an alkyl bromide and thiourea to form an alkyl tso-thiourea, followed by hydrolysis of the latter with sodium hydroxide solution, for example ... 

The latter upon decomposition with dilute hydrochloric acid yields laevo sec.-octyl hydrogen phthalate the crystalline brucine salt, when similarly treated, affords the dextro sec.-octyl hydrogen phthalate. These are reerystallised and separately hydrolysed with sodium hydroxide solution to yield pure I- and d-sec.-octyl alcohols ... 

If the presence of unreduced nitrobenzene is suspected (odour and/or high b.p. residue), treat all the product with excess of dilute hydrochloric acid and remove the nitrobenzene either by steam distillation or by ether extraction render the residue alkaline with sodium hydroxide solution and isolate the aniline os before. 

SULPHONATION OF AROMATIC AMINES If aniline is treated with excess of concentrated sulphuric acid and the resulting mixture, which contains aniline sulphate, is heated at 180° until a test portion when mixed with sodium hydroxide solution no longer liberates aniline, p-aminobenzenesulphonic acid or sulphanilic acid is formed this separates as the dihydrate upon pouring the cooled mixture into water. The reaction prohahly proceeds as follows ... 

Place a mixture of 25 g. of a-naphthylamine (Section IV,37) and 125 g. (69 -5 ml.) of concentrated sulphuric acid in a 250 ml. conical or round-bottomed flask, and heat in an oil bath for 4-5 hours or until a test sample, when made alkaline with sodium hydroxide solution and extracted with ether, yields no naphthylamine upon evaporation of the ether. Pour the warm reaction mixture cautiously and with stirring into 300 ml. of cold... 

It is not advisable to treat the crude jo-nitroplieriol with sodium hydroxide solution in order to convert it into the sodium derivative alkali causes extensive resiniflcation. 

Sodium hydroxide solution cannot be used at this stage since it may produce benzoic acid by the Cannizzaro reaction (Section IV,123) from any unchanged benzaldehyde. If, however, the reaction mixture is diluted with 3-4 volumes of water, steam distilled to remove the unreacted benzaldehyde, the residue may then be rendered alkaline with sodium hydroxide solution. A few grams of decolourising carbon are added, the mixture boiled for several minutes, and filtered through a fluted filter paper. Upon acidifying carefully with concentrated hydrochloric acid, cinnamic acid is precipitated. This is collected, washed and purified as above. 

The solution will then contain the free acid and the hydrochloride of the base either of these may separate if sparingly soluble. If a sohd crystallises from the cold solution, filter, test with sodium bicarbonate solution compare Section 111,85, (i) and compare the m.p. with that of the original compound. If it is a hydrolysis product, examine it separately. Otherwise, render the filtrate alkahne with sodium hydroxide solution and extract the base with ether if the presence of the unchanged acyl canpound is suspected, extract the base with weak acid. Identify the base in the usual manner (see Section IV, 100). The acid will be present as the sodium salt in the alkaline extract and may be identified as described in Section IV,175. 

Furfural undergoes the Cannizzaro reaction (compare Benzaldehyde Section IV,123) when treated with sodium hydroxide solution ... 

Phthalonitrile. In a 1 litre round-bottomed flask, provided with a reflux condenser, place 100 g. of phthalamide and 350 ml. of acetic anhydride. Reflux for 5-6 hours. Add the reaction product whilst still hot cautiously to 700 ml. of boiling water this decomposes the excess of acetic anhydride. Cool in ice, and then render the reaction mixture alkaline with sodium hydroxide solution. Filter ofiF the precipitated crystals at the pump, wash with water, and dry at 100°. The yield of the crude nitrile is 70 g. After one or two recrystallisations from benzene, the m.p. should be 141°—that of pure phthalonitrile. It is usually best to distil the crude nitrile under reduced pressure (Figs. II, 19, 3-4) the distillate has m.p. 137-138°, and the m.p. is raised to 141° after one recrystallisation from benzene. 

The essential basis of the scheme for the separation of water-soluble compounds is, therefore, distillation of (a) an aqueous solution of the mixture, (b) an alkaline (with sodium hydroxide) solution of the mixture, and (c) an acidic (with sulphuric oj phosphoric acid) solution of the mixture. The residue will contain the non-volatile components, which must be separated from inorganic salts and from each other by any suitable process. 

Now distil the filtrate A) and collect the distillate as long as it is acid to litmus. Should any solid separate out in the distilhng flask during the distUlation, add more water to dissolve it. Set aside the residue B) in the flask. Identify the volatile acid in the distihate. A simple method is to just neutralise it with sodium hydroxide solution, evaporate to dryness and convert the residual sodium salt into the S-benzyl-iao-thiuTonium salt (Section 111,85,5). 

The mercury contained in the mother Hquid and washings of either method is recovered by treatment with sodium hydroxide solution. Yellow mercuric oxide is precipitated and filtered. The filtrate is treated further to remove the last traces of mercury before it is discarded. 

For crystal sulfamic acid assay, a simplified procedure of neutralization titration with sodium hydroxide solution may be used. At the end point, Bromothymol Blue (BTB) indicator changes color from yellow to yellowish green. A 1-mL solution of l/2NNaOH is equivalent to 0.0485 g of sulfamic acid. 

Almost all sodium cyanide is manufactured by the neutralization or wet processes in which hydrogen cyanide reacts with sodium hydroxide solution. 

In a copper or iron kettle of 4-I. capacity is placed a solution of 200 g. of d-tartaric acid and 700 g. of sodium hydroxide in 1400 cc. of water. A 12-I. flask through which cold water is run is placed in the mouth of the kettle in order to prevent loss of water vapor, and the mixture is boiled gently over an open flame for four hours. The solution is now transferred to a 12-I. flask or crock and partially neutralized with 1400 cc. of commercial hydrochloric acid (density 1.19). To the still alkaline solution is now added just enough sodium sulfide to precipitate all the iron or copper which has been dissolved from the kettle (Note i). The filtered solution is then just acidified with hydrochloric acid, boiled to expel all hydrogen sulfide, and made very faintly alkaline to phenolphthalein with sodium hydroxide solution. To the hot solution is then added a concentrated solution of 300 g. of anhydrous calcium chloride which causes an immediate precipitation of calcium tff-tartrate and mesotartrate. 

Treat the sample for 30 to 40 imn with sodium hydroxide solution (c = 1 mol/1) at 80 °C Apply sample solution and then 0 2% dansyl chloride over It Cover with a glass plate and allow to react in the dark at room temperature for 60 mm, then chromatograph... 

Spray solution II Dissolve 92 mg potassium hydrogen phthalate in 100 ml water and adjust the pH to 5.0 with sodium hydroxide solution (1 mol/l). Dissolve 5 g sodium perchlorate in this solution [9]. 

Acetylene derivatives and substances containing labile halogen The dried chromatograms are homogeneously sprayed with spray solution I, dried in a stream of hot air and sprayed once more with the same solution. The color can then be intensified by spraying with sodium hydroxide solution (10 mol/1) [8]. 

This formula was confirmed hy Haworth and Perkin s synthesis of a-flZZocryptopine from herherine, the first application of a process, of which examples have heen given already in the syntheses of cryptopine (p. 298) and protopine (p. 301) hy the same authors. Anhydrotetrahydromethyl-herherine (I cf. hase (a), p. 346) in dry chloroform was added to a solution of perhenzoic acid in ether cooled helow 5°. The amine oxide, C21H23O5N (II), separated as an oil, which after shaking with sodium hydroxide solution, solidified and was crystallised from water in slender prisms, m.p. 135°. It was dissolved in acetic acid, hydrochloric acid added, the mixture heated in boiling water for an hour and the hase precipitated hy addition of potassium hydroxide. The precipitate was dissolved in methyl alcohol, ether added, the alcohol washed out with water and the ethereal... 

When monocrotaline is hydrogenolysed the acid scission product is monocrotalic acid, CgHigOj, m.p. 181-2°, [a]p ° — 5-33° (HgO), which provides a methyl ester, m.p. 79-80°, [ ]d°° — 16-2° (EtOH), containing one active H atom and a p-bromophenacyl ester, m.p. 162-3°. It is a lactonic acid, which on boiling with sodium hydroxide solution loses carbon dioxide and produces a/3-dimethyllaevulic acid (monocrotic acid, II). 

HgO), but which regenerates the N-benzoyl derivative on recovery of the base with sodium hydroxide solution.. Similar migrations of the acyl group in this type of alkaloid have been recorded by Nagai and Kanao. ... 

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