Hydrolysate dilute-acid

Hydrolysed by dilute acids and alkalis to aniline. It chlorinates more slowly than aniline to o-and p-chloroacetanilides. 

Prepared by the dehydration of benzamide. Hydrolysed by dilute acids and alkalis to benzoic acid. Good solvent. benzopheDone,C]3HioO,PhC(0)Ph. Colourless rhombic prisms, m.p. 49 C, b.p. 306°C. Characteristic smell. It is prepared by the action of benzoyl chloride upon benzene in the presence of aluminium chloride (Friedel-Crafts reaction) or by the oxidation of di-phenylmethane. It is much used in perfumery. Forms a kelyl with sodium. 

Prepared by stirring phthalimide with cold concentrated ammonia solution. Hydrolysed to phlhalic acid with dilute acids. Dehydration with ethanoic anhydride gives first n-cyano-benzamide and then phthalonitrile. 

Colourless needles m.p. 14rC, b.p. 290"C. Slowly hydrolysed to phthalic acid by dilute acids and alkalis. 

Hydrobenzamide is readily hydrolysed even by cold dilute acids. 

Hydrolysis by acids. Sucrose is readily hydrolysed by dilute acids. Dissolve 0 5 g. of sucrose in 5 ml. of water, add 2 ml. of dil. H2SO4 and heat in a boiling water-bath for 5 minutes. Cool and show that the solution has reducing properties, and will form glucosazone. Note that the excess of acid must be neutralised before carrying out the reduction tests. 

Acetals are usually liquid they are almost unaffected by alkalis and are not attacked by metallic sodium nor by Fehling s solution. They are identified by reference to the alcohol and aldehyde (or ketone if a ketal) which they yield when hydrolysed in acid solution. Hydrolysis proceeds readily in dilute acid solution e.g., with 3-5 per cent, acid). ... 

The above simple experiments illustrate the more important properties of aliphatic acid chlorides. For characterisation, the general procedure is to hydrolyse the acid chloride by warming with dilute alkali solution, neutralise the resulting solution with dilute hydrochloric acid (phenol-phthalein), and evaporate to dryness on a water bath. The mixture of the sodium salt of the acid and sodium chloride thus obtained may be employed for the preparation of solid esters as detailed under Aliphatic Acids, Section 111,85. The anilide or p-toluidide may be prepared directly from the acid chloride (see (iii) above and Section III,85,i). 

Of the common disaccharides sucrose does not reduce Fehling s solution. If the cane Sugar is hydrolysed by boiling it with dilute acid and the solution is neutralised with aqueous sodium hydroxide, the reduction of Fehling s solution occurs readily. 

Cellulose. This is insoluble in water, hot and cold. It dissolves in a solution of Schweitzer s reagent (precipitated cupric hydroxide is washed free from salts and then dissolved in concentrated ammonia solution), from which it is precipitated by the addition of dilute acids. Cellulose is not hydrolysed by dilute hydrochloric acid. 

Place 10 ml. of pure benzaldehyde (Section IV,115) and 100 ml. of concentrated aininonia solution (sp. gr. 0-88) in a 250 ml. wide-mouthed reagent bottle. Cork the bottle securely, shake vigorously for 10 minutes and allow to stand with occasional shaking for 24 hours. By this time the benzaldehyde should be converted into a hard mass of hydrobenz-amide. Break up the solid mass with a spatula or a thick glass rod, filter with suction, wash with water, and drain thoroughly. RecrystalUse from absolute alcohol (or absolute methylated spirit). The yield of hydrobenzamide (colourless crystals), m.p. 101°, is 7 g. It is easily hydrolysed by cold dilute acids. 

Acetals RCH(OR )2 are stable in alkaline solution, but are readily hydrolysed by dilute acids to give aldehydes, which may be characterised as detailed under 4 (see SectionIII,69). 

Imides (e.g. phthalimide) can be purified by conversion to their potassium salts by reaction in ethanol with ethanolic potassium hydroxide. Hie imides are regenerated when the salts are hydrolysed with dilute acid. Like amides, imides readily crystallise from alcohols and, in some cases (e.g. quinolinic imide), from glacial acetic acid. 

Ketones are more stable to oxidation than aldehydes and can be purified from oxidisable impurities by refluxing with potassium permanganate until the colour persists, followed by shaking with sodium carbonate (to remove acidic impurities) and distilling. Traces of water can be removed with type 4A Linde molecular sieves. Ketones which are solids can be purified by crystallisation from alcohol, toluene, or petroleum ether, and are usually sufficiently volatile for sublimation in vacuum. Ketones can be further purified via their bisulfite, semicarbazone or oxime derivatives (vide supra). The bisulfite addition compounds are formed only by aldehydes and methyl ketones but they are readily hydrolysed in dilute acid or alkali. 

Recrystd from Me2CO, H2O or Et0H-Et20 and dried. Soluble in H2O (60%) and EtOH (5%) but insol in Et20 and slightly in CHCI3. The hydrochloride has m 300 (from Mc2CO). The free base is a viscous liquid which forms a crystalline hydrate with m 59 and [a] -28° (c 2.7, H2O). Readily hydrolysed in dilute acid or base. [Meinwald J Chem Soc 712 7953 Fodor Tetrahedron 1 86 1957.]... 

When the alkaloid is heated with water at 150°, or boiled with dilute acids, it is hydrolysed into hydrocotarnine, and opianic acid. Similar decompositions are induced by acid oxidation or acid reduction, thus (1) dilute nitric acid furnishes opianic acid, CjoHioOj, and cotarnine, C12H15O4N (2) zinc and hydrochloric acid produce meconin, C10H10O4, and hydrocotarnine, C12H15O3N. 

The carbides of Cr, Mn, Fe, Co and Ni are much more reactive than the interstitial carbides of the earlier transition metals. They are rapidly hydrolysed by dilute acid and sometimes even by water to give H2 and a mixture of hydrocarbons. For example, M3C give H2 (75%), CH4 (15%)... 

Sn02, cassiterite, is the main ore of tin and it crystallizes with a rutile-type structure (p. 961). It is insoluble in water and dilute acids or alkalis but dissolves readily in fused alkali hydroxides to form stannates M Sn(OH)6. Conversely, aqueous solutions of tin(IV) salts hydrolyse to give a white precipitate of hydrous tin(IV) oxide which is readily soluble in both acids and alkalis thereby demonstrating the amphoteric nature of tin(IV). Sn(OH)4 itself is not known, but a reproducible product of empirical formula Sn02.H20 can be obtained by drying the hydrous gel at 110°, and further dehydration... 

It is intermediate in reactivity between SF4 and the very inert SFg. Unlike SF4 it is not hydrolysed by water or even by dilute acids or alkalis and, unlike SFg, it is extremely toxic. It disproportion-ates readily at 150° probably by a free radical mechanism involving SF5 (note the long, weak S-S bond Fig. 15.20) ... 

Chlorophthalazine is quite reactive to many basic nucleophiles but reacts sluggishly with aqueous or alcoholic alkali. In contrast, it is very rapidly hydrolyzed by warm, concentrated hydrochloric acid as are its diazine isomers. In hydrolysis with very dilute acid or with water, it forms some phthalazinone but mostly the self-con-densation product which hydrolyses to give 2-(l -phthalazinyl)-phthalazin-l-one (70% yield). Such self-condensations in diazanaph-thalenes and in monocyclic azines are always acid-catalyzed (Sections II, C and III,B). With methanolic methoxide, 1-chlorophthalazine (65°, few mins), its 7-methoxy analog (20°), and 1,6- and 1,7-dichlorophthalazines (20°) readily undergo mono-substitution. 

Determination of silver as chloride Discussion. The theory of the process is given under Chloride (Section 11.57). Lead, copper(I), palladium)II), mercury)I), and thallium)I) ions interfere, as do cyanides and thiosulphates. If a mercury(I) [or copper(I) or thallium(I)] salt is present, it must be oxidised with concentrated nitric acid before the precipitation of silver this process also destroys cyanides and thiosulphates. If lead is present, the solution must be diluted so that it contains not more than 0.25 g of the substance in 200 mL, and the hydrochloric acid must be added very slowly. Compounds of bismuth and antimony that hydrolyse in the dilute acid medium used for the complete precipitation of silver must be absent. For possible errors in the weight of silver chloride due to the action of light, see Section 11.57. 

Substituted amides suffer hydrolysis with greater difficulty. The choice of an acid or an alkaline medium vill depend upon (a) the solubility of the compound in the medium and (b) the effect of the reagent upon the products of hydrolysis. Substituted amides of comparatively low molecular weight (e.g., acetanilide) may be hydrolysed by boiling either with 10 per cent, sodium hydroxide solution or with 10 per cent, sulphuric acid for 2-3 hours. Other substituted amides are so insoluble in water that little reaction occurs when they are refluxed with dilute acid or dilute alkali for several hours. These include such substances as benzanilide (C(H(CONHC,Hg) and the benzoyl derivative of a naphthylamine (C.HjCONHCioH,) or a toluidine (C gCONHCjH,). For these substances satisfactory results may be obtained with 70 per cent, sulphuric acid this hydrolysis medium is a much better solvent for the substituted amide than is water or more dilute acid it also permits a higher reaction temperature (compare Section IV 192) ... 

The compound, produced as an hydrate from dilute acid hydrolyses of disodium azotetrazolide, exploded on heating for analytical purposes. 

Methyl vinyl ether is rapidly hydrolysed by contact with dilute acids to form acetaldehyde, which is more reactive and has wider flammability limits than the ether [1], Presence of base is essential during storage or distillation of the ether to prevent rapid acid-catalysed homopolymerisation, which is not prevented by antioxidants. Even mildly acidic solids (calcium chloride or some ceramics) will initiate exothermic polymerisation [2],... 

Dilute acid (0.5 M- 2.5 M H2S04) - extractable C or carbohydrate - C have also been used as indicators of soil organic matter status (Angers and Mehuys 1989 Chan and Heenan 1999 Shepherd et al. 2001). The acid hydrolysable fraction generally accounts for about 20-40% of total organic C (Rovira and Vallejo 2002) and 65-85% of the total soil carbohydrate pool (Puget et al. 1999). 

Although the trisamido species 35 are resistant to hydrolysis in both acidic and alkali solutions, the toamido species 36 are hydrolysed immediately by refluxing in water, dilute acids or bases.62... 

At higher temperatures the monomer is the predominant species although the rate of hydrolysis to U03 is increased. U03 dissolves in uranyl solutions to give U02OH+ and polymerised hydroxo-bridged species. Polynuclear species could arise from U4+ as it hydrolyses in dilute acid solutions. Complex ions are formed with thiocyanate, phosphate, citrate and anions of other organic acids. 

Alkyl vinyl ethers [213], systems analogous to enamines, are readily hydrolysed by dilute acid to acetaldehyde and the... 

Aromatic acid chlorides react with phosphine at 50 °C in absolute pyridine to form mono-, di- and triacylphosphines. For example, PH3 and benzoyl chloride give tribenzoylphosphine, a yellow crystalline compound which is resistent to water and dilute acids but is hydrolysed to PH3 and alkali benzoate by alkalis... 

Doree (Ref 3) describes them as a polysaccharides, which in their natural state are insoluble in boiling water, but readily soluble in dilute caustic and easily hydrolysable on warming with dilute acids... 

Azidoguanidine is not decomposed by boiling in water. It is, however, hydrolysed on treatment with concentrated sodium hydroxide to form sodium azide. Under the influence of a dilute solution of sodium hydroxide or of dilute acids it is isomerized to 5-aminotetrazole (V) ... 

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