Solubility in alkalis

There are complications in applying the Hinsberg test to certain amines containing hydroxyl, nitro and carboxyl groups, e.g., p-N-methylamiiiobenzoic acid CHjNHC.HjCOOH (I 4) may behave in this test as a primary amine (soluble in alkali) so that it is essential to consider the properties of the original compound in conjunction with the results of the test. 

If the benzoyl derivative is soluble in alkali, precipitate it together with the benzoic acid derived from the reagent by the addition of hydrochloric acid filter and extract the product with cold ether or light petroleum (b.p. 40-60°) to remove the benzoic acid. 

Derivatives with 3-nitrophthalic anhydride. 3-Nitrophthalic anhydride reacts with primary and secondary amines to yield nitro-phthalamic acids it does not react with tertiary amines. The phthalamic acid derived from a primary amine undergoes dehydration when heated to 145° to give a neutral A -substituted 3-nitrophthalimide. The phthalamic acid from a secondary amine is stable to heat and is, of course, soluble in alkali. The reagent therefore provides a method for distinguishing and separating a mixture of primary and secondary amines. 

Polonium is readily dissolved in dilute acids, but is only slightly soluble in alkali. Polonium slats of organic acids char rapidly halide amines are reduced to the metal. 

Lead nitrate [10099-74-8] Pb(N02)2, mol wt 331.23, sp gr 4.53, forms cubic or monoclinic colorless crystals. Above 205°C, oxygen and nitrogen dioxide are driven off, and basic lead nitrates are formed. Above 470°C, lead nitrate is decomposed to lead monoxide and Pb O. Lead nitrate is highly soluble in water (56.5 g/100 mL at 20°C 127 g/100 mL at 100°C), soluble in alkalies and ammonia, and fairly soluble in alcohol (8.77 g/100 mL of 43% aqueous ethanol at 22°C). Lead nitrate is readily obtained by dissolving metallic lead, lead monoxide, or lead carbonate in dilute nitric acid. Excess acid prevents the formation of basic nitrates, and the desired lead nitrate can be crystallized by evaporation. 

The solubility in alkali sulfide solutions stems from the presence of disulfide groups —S—S— in ortho position to the terminal amino groups. These disulfide groups are reduced to the mercapto groups —SH, which are soluble in alkaU. 

The requirements of a developer moiety for incorporation into a dye developer are well fulfilled by hydroquinones. Under neutral or acidic conditions hydroquinones are very weak reducing agents and the weakly acidic phenoHc groups confer tittle solubility. In alkali, however, hydroquinones are readily soluble, powerful developing agents. Dye developers containing hydroquinone moieties have solubility and redox characteristics in alkali related to those of the parent compounds. 

Citrazinic acid (2,6-dihydroxyisonicotinic acid) [99-11-6] M 155.1, m >300°, pK] 3.0, pK2 4.76. Yellow powder with a greenish shade, but is white when ultra pure and turns blue on long standing. It is insoluble in H2O but slightly soluble in hot HCl and soluble in alkali or carbonate solutions. Purified by precipitation from alkaline solutions with dilute HCl, and dry in a vacuum over P2O5. The ethyl ester has m 232° (evacuated tube) and a pKa of 4.81 in MeOCH2CH20H [IR Pitha Coll Czech Chem Comm 28 1408 1963]. 

Naphthazarin (5,8-dihydroxy-1,4-naphthoquinone) [475-38-7] M 190.2, m 220-230°(dec), m 225-230°, pKEst(i) 9.5, pKEst(2) ll-l Red-brown needles with a green shine from EtOH. Also recrystd from hexane and purified by vacuum sublimation. [Huppert et al. J Phys Chem 89 5811 1985.] It is sparingly soluble in H2O but soluble in alkalis. It sublimes at 2-10mm. The diacetate forms golden yellow prisms from CHCI3, m 192-193° and the 5,8-dimethoxy derivative has m 157° (155°) (from pet ether) [Bruce and Thompson J Chem Soc 1089 7955 IR Schmand and Boldt J Am Chem Soc 97 447 1975 NMR Brockmann and Zeeck Chem Ber 101 4221 1968]. The monothiosemicarbazone has m 168°(dec) from EtOH [Gardner et al. J Am Chem Soc 74 2106 7952]. 

Rhodium (III) chloride [10049-07-7] M 209.3, m >100°(dec), b 717°. Probable impurities are KCl and HCl. Wash solid well with small volumes of H2O to remove excess KCl and KOH and dissolve in the minimum volume of cone HCl. Evaporate to dryness on a steam bath to give wine-red coloured RhCl3.3H20. Leave on the steam bath until odour of HCl is lost - do not try to dry further as it begins to decompose above 100° to the oxide and HCL. It is not soluble in H2O but soluble in alkalis or CN solns and forms double salts with alkali chlorides. [Inorg Synth 7 214 1063.]... 

Anhalamine, C11H15O3N, occurs in microscopic needles, m.p. 187-8°. The hydrochloride, B. HCl. 2HjO, forms lustrous leaflets, m.p. 256-8° and the sulphate, Bg. H2SO4, colourless prisms the picrate has m.p. 234-6°. The base contains two methoxyl groups and one hydroxyl group. A dibenzoyl derivative, m.p. 128-9°, and a monobenzoyl derivative, m.p. 167-5°, are formed, the latter but not the former being soluble in alkalis. The methyl ether of anhalamine is identical with anhalinine, b.p. 130 0°/0-01 mm., m.p. 61-3°, and the A-methyl derivative is anhalidine, m.p. 131-3°. 

Tuduranine, CjgHjgOgN. This member of the aporphine group (p. 306) is the most recent addition to Sinomenium alkaloids and was isolated by Goto from the mother liquors of sinomenine. It is crystalline, has m.p. 125° (with softening at 105°), and yields a sparingly soluble hydrochloride, m.p. 286° (dec.), [a] f — 148° (dilute MeOH), is freely soluble in alkali, and gives feeble ferric chloride and diazo-colour reactions and a fuchsin-red colour with formaldehyde and sulphuric acid. It behaves as a secondary base and yields a diacetyl derivative, m.p. 170°, [a] / — 321-71° (MeOH), which does not form a methiodide, but can be hydrolysed to A -acetyl-tuduranine, m.p. 277°, — 395-24°, and this can be methylated to... 

Muricinine, CijHj g02N(0Me)2. Isolated as the perchlorate, m.p. 206-8°. The base does not contain a dioxymethylene group, is soluble in alkalis and gives a green colour with ferric chloride. ... 

Berberilic acid, CgoHjgOgN, m.p. 177-82°, is dibasic, and furnishes a dimethyl ester, m.p. 173°. When heated to about 180°, the acid passes into ANHYDROBERBERiLic ACID, CjgHjjOgN, colourless needles, m.p. 236°, soluble in alkali carbonate solutions with the formation of berberilates. When ammonium berberilate is dried under reduced pressure, a molecular proportion of ammonia is lost with the formation of the ammonium salt of the anhydro-acid, from which other salts, and the methyl ester, m.p. 178°, have been obtained. Berberilic acid is hydrolysed by hot dilute sulphuric acid to hemipinic acid (I) and oi-aminoethylpiperonylic acid (II), large tabular crystals, m.p. 180-2°. Berberilic acid is therefore represented by (III). 

From a spurious angostura bark, Troger isolated an unnamed alkaloid, ( jjHjgOjNj, m.p. 167°, soluble in alkali or acid and giving a a ystallinc perchlorate and methiodide. 

Properties. Orange needles m. p. 2Sc>—290 tsuhlinit-completely at 140 without decomposition soluble in alkali with a deep purple coloui (sodium alizarate).. It is i-ocluced t( anthracene on heating with diy zinc dust. 

Thi portion ot both oils which was soluble in alkali consisted of pure toethyl salieylate. Tha acid separated therefrom had a melling-point of priicisely 155 0° C.. which is that o pure sallcylio acid, aud it... 

Its solubility characteristics in aqueous systems are such that retention of toxicity to insects by dissolved crystal protein is always suspect, and loss of activity on dissolution owing to denaturation is often observed. The protein is soluble only in relatively strong aqueous alkali. Thus, it has been variously reported to be soluble in 0.01N- to 0.05N sodium hydroxide (1) and alkali at pH 10.5 in the presence of thioglycollate (35) we have also observed its solubility in alkali at pH 9.5 in the presence of urea and potassium boro hydride. One difference between the characteristic proteins produced by various strains of crystalliferous bacilli is observed in the degree of alka-... 

The treatment of sulfonyl chlorides with ammonia or amines is the usual way of preparing sulfonamides. Primary amines give N-alkyl sulfonamides, and secondary amines give N,N-dialkyl sulfonamides. The reaction is the basis of the Hinsberg test for distinguishing between primary, secondary, and tertiary amines. N-Alkyl sulfonamides, having an acidic hydrogen, are soluble in alkali, while N,N-dialkyl sulfon-... 

Alkyl mercaptans are partly soluble in solutions of caustic alkalis, but their salts are hydrolysed in dilute aqueous solution back to the free mercaptans. Thiophenols are soluble in alkali hydroxide solutions. Upon treatment with sodium, hydrogen is evolved. 

Organic solvent(s) Partition coefficients No data 1 g in 2,500 mL absolute alcohol 1 g in 75 mL absolute alcohol Soluble in alkali chlorides soluble in alkali (Massicot) insoluble in alcohol Soluble in fixed alkali hydroxides insoluble in alcohol... 

Phosphonates are useful additions in acidification treatments after alkaline processing to assist in the removal of metal compounds that have limited solubility in alkali. 

The low-substituted hydroxyethylcellulose which, like methyl- and ethylcellulose, is soluble in alkali, particularly when cooled, has much to recommend it from an industrial point of view. It can be formed by the action of only small quantities (0.25 to 0.5 moles) of ethylene oxide on alkali cellulose.47 The reaction product need not be isolated since there are no salts formed, but may be diluted with water or weak alkali to give a spinning solution. The product should therefore be quite cheap. Preparation and properties of hydroxyethylcellulose have been discussed by Schorger and Shoemaker.47... 

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